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<channel>
	<title>Richard Knop&#039;s Zend Framework Blog</title>
	<atom:link href="http://blog.richardknop.com/feed/" rel="self" type="application/rss+xml" />
	<link>http://blog.richardknop.com</link>
	<description>Zend Framework, PHP, MySQL, jQuery, JavaScript, AJAX, SEO, E-commerce and more</description>
	<lastBuildDate>Fri, 05 Mar 2010 21:27:17 +0000</lastBuildDate>
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			<item>
		<title>Zend Framework IE conditional stylesheets and scripts</title>
		<link>http://blog.richardknop.com/2010/03/zend-framework-ie-conditional-stylesheets-and-scripts/</link>
		<comments>http://blog.richardknop.com/2010/03/zend-framework-ie-conditional-stylesheets-and-scripts/#comments</comments>
		<pubDate>Fri, 05 Mar 2010 21:27:17 +0000</pubDate>
		<dc:creator>Richard Knop</dc:creator>
				<category><![CDATA[PHP]]></category>
		<category><![CDATA[Web design]]></category>
		<category><![CDATA[Zend Framework]]></category>
		<category><![CDATA[IE conditional comments in Zend Framework]]></category>
		<category><![CDATA[Zend view helpers]]></category>

		<guid isPermaLink="false">http://blog.richardknop.com/?p=559</guid>
		<description><![CDATA[You can append a conditional stylesheet in a controller action like this:



$this-&#62;view-&#62;headLink&#40;&#41;-&#62;appendStylesheet&#40;&#39;/path/to/some/styles.css&#39;, &#39;screen&#39;, &#39;IE 8&#39;&#41;;



Which would produce this markup:
&#60;!--[if IE 8]&#62; &#60;link href="/path/to/some/styles.css" media="screen" rel="stylesheet" type="text/css" /&#62;&#60;![endif]--&#62;
Adding a conditional JavaScript file is similar:



$this-&#62;view-&#62;headScript&#40;&#41;-&#62;appendFile&#40;&#39;/path/to/some/script.js&#39;, &#39;text/javascript&#39;, array&#40;&#39;conditional&#39; =&#62; &#39;IE&#39;&#41;&#41;;



And that would produce markup like this:
&#60;!--[if IE]&#62; &#60;script type="text/javascript" src="/path/to/some/script.js"&#62;&#60;/script&#62;&#60;![endif]--&#62;
It can pretty useful when you need to use [...]]]></description>
			<content:encoded><![CDATA[<p>You can append a conditional stylesheet in a controller action like this:</p>
<div class="geshi no php">
<ol>
<li class="li1">
<div class="de1"><span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">view</span><span class="sy0">-&gt;</span><span class="me1">headLink</span><span class="br0">&#40;</span><span class="br0">&#41;</span><span class="sy0">-&gt;</span><span class="me1">appendStylesheet</span><span class="br0">&#40;</span><span class="st0">&#39;/path/to/some/styles.css&#39;</span><span class="sy0">,</span> <span class="st0">&#39;screen&#39;</span><span class="sy0">,</span> <span class="st0">&#39;IE 8&#39;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
</ol>
</div>
<p>Which would produce this markup:</p>
<pre>&lt;!--[if IE 8]&gt; &lt;link href="/path/to/some/styles.css" media="screen" rel="stylesheet" type="text/css" /&gt;&lt;![endif]--&gt;</pre>
<p>Adding a conditional JavaScript file is similar:</p>
<div class="geshi no php">
<ol>
<li class="li1">
<div class="de1"><span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">view</span><span class="sy0">-&gt;</span><span class="me1">headScript</span><span class="br0">&#40;</span><span class="br0">&#41;</span><span class="sy0">-&gt;</span><span class="me1">appendFile</span><span class="br0">&#40;</span><span class="st0">&#39;/path/to/some/script.js&#39;</span><span class="sy0">,</span> <span class="st0">&#39;text/javascript&#39;</span><span class="sy0">,</span> <span class="kw3">array</span><span class="br0">&#40;</span><span class="st0">&#39;conditional&#39;</span> <span class="sy0">=&gt;</span> <span class="st0">&#39;IE&#39;</span><span class="br0">&#41;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
</ol>
</div>
<p>And that would produce markup like this:</p>
<pre>&lt;!--[if IE]&gt; &lt;script type="text/javascript" src="/path/to/some/script.js"&gt;&lt;/script&gt;&lt;![endif]--&gt;</pre>
<p>It can pretty useful when you need to use IE conditional comments just for a single controller action. Otherwise, if it applies site-wide, it&#8217;s better to just put conditional stylesheets and/or scripts in a layout file.</p>
]]></content:encoded>
			<wfw:commentRss>http://blog.richardknop.com/2010/03/zend-framework-ie-conditional-stylesheets-and-scripts/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
		</item>
		<item>
		<title>A Simple Search Engine Implementing Zend_Search_Lucene</title>
		<link>http://blog.richardknop.com/2010/03/a-simple-search-engine-implementing-zend_search_lucene/</link>
		<comments>http://blog.richardknop.com/2010/03/a-simple-search-engine-implementing-zend_search_lucene/#comments</comments>
		<pubDate>Mon, 01 Mar 2010 15:51:36 +0000</pubDate>
		<dc:creator>Richard Knop</dc:creator>
				<category><![CDATA[MySQL]]></category>
		<category><![CDATA[PHP]]></category>
		<category><![CDATA[Zend Framework]]></category>
		<category><![CDATA[Zend_Search_Lucene]]></category>

		<guid isPermaLink="false">http://blog.richardknop.com/?p=555</guid>
		<description><![CDATA[Zend_Search_Lucene is a PHP port of a popular Java search engine Apache Lucene. It is also an important part of Zend Framework. Some say that it is too sluggish to be used in robust web applications and recommend faster alternatives such as Sphinx but that is not today&#8217;s topic. In this post I will show [...]]]></description>
			<content:encoded><![CDATA[<p><a href="http://framework.zend.com/manual/en/zend.search.lucene.html">Zend_Search_Lucene</a> is a PHP port of a popular Java search engine <a href="http://lucene.apache.org/java/docs/">Apache Lucene</a>. It is also an important part of Zend Framework. Some say that it is too sluggish to be used in robust web applications and recommend faster alternatives such as <a href="http://www.sphinxsearch.com/">Sphinx</a> but that is not today&#8217;s topic. In this post I will show you a basic implementation of Zend_Search_Lucene that has worked well so far for medium websites I have worked on. There are two main tasks you will have to take care of:</p>
<ol>
<li>Creating an index and updating it regularly.</li>
<li>Searching the index with a powerful <a href="http://framework.zend.com/manual/en/zend.search.lucene.query-language.html">query language</a>.</li>
</ol>
<p>First, let&#8217;s create a fresh search index. I know it&#8217;s already tiresome but I will use a simple blog application for my example implementation. To simplify it even further, it will only be possible to search blog posts. The posts schema looks like this:</p>
<pre>CREATE TABLE posts (
id INT NOT NULL AUTO_INCREMENT,
title VARCHAR(255) NOT NULL,
body TEXT NOT NULL,
created_at DATETIME NOT NULL,
updated_at DATETIME NOT NULL,
user_id INT NOT NULL,
INDEX (created_at),
INDEX (user_id),
FOREIGN KEY (user_id)
REFERENCES users(id)
ON UPDATE CASCADE
ON DELETE CASCADE,
PRIMARY KEY (id)
) ENGINE = INNODB;</pre>
<p>Creating the search index is easy:</p>
<div class="geshi no php">
<ol>
<li class="li1">
<div class="de1">Zend_Search_Lucene<span class="sy0">::</span><span class="me2">setDefaultSearchField</span><span class="br0">&#40;</span><span class="st0">&#39;contents&#39;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// create blog posts index located in /data/posts_index</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// make sure the folder is writable</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$index</span> <span class="sy0">=</span> Zend_Search_Lucene<span class="sy0">::</span><span class="me2">create</span><span class="br0">&#40;</span><span class="st0">&#39;data/posts_index&#39;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// $this-&gt;_getTable() is a method that returns a model</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// get() method of the model returns all posts from the database</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$posts</span> <span class="sy0">=</span> <span class="re1">$this</span><span class="sy0">-&gt;</span>_getTable<span class="br0">&#40;</span><span class="st0">&#39;Posts&#39;</span><span class="br0">&#41;</span><span class="sy0">-&gt;</span><span class="me1">get</span><span class="br0">&#40;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// iterate through posts and build the index</span></div>
</li>
<li class="li1">
<div class="de1"><span class="kw1">foreach</span> <span class="br0">&#40;</span><span class="re1">$posts</span> <span class="kw1">as</span> <span class="re1">$p</span><span class="br0">&#41;</span> <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="re1">$doc</span> <span class="sy0">=</span> <span class="kw2">new</span> Zend_Search_Lucene_Document<span class="br0">&#40;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="re1">$doc</span><span class="sy0">-&gt;</span><span class="me1">addField</span><span class="br0">&#40;</span>Zend_Search_Lucene_Field<span class="sy0">::</span><span class="me2">UnIndexed</span><span class="br0">&#40;</span><span class="st0">&#39;entry_id&#39;</span><span class="sy0">,</span> <span class="re1">$p</span><span class="sy0">-&gt;</span><span class="me1">id</span><span class="br0">&#41;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="re1">$doc</span><span class="sy0">-&gt;</span><span class="me1">addField</span><span class="br0">&#40;</span>Zend_Search_Lucene_Field<span class="sy0">::</span><span class="me2">Keyword</span><span class="br0">&#40;</span><span class="st0">&#39;title&#39;</span><span class="sy0">,</span> <span class="re1">$p</span><span class="sy0">-&gt;</span><span class="me1">title</span><span class="br0">&#41;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="re1">$doc</span><span class="sy0">-&gt;</span><span class="me1">addField</span><span class="br0">&#40;</span>Zend_Search_Lucene_Field<span class="sy0">::</span><span class="me2">UnStored</span><span class="br0">&#40;</span><span class="st0">&#39;contents&#39;</span><span class="sy0">,</span> <span class="re1">$p</span><span class="sy0">-&gt;</span><span class="me1">body</span><span class="br0">&#41;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="re1">$index</span><span class="sy0">-&gt;</span><span class="me1">addDocument</span><span class="br0">&#40;</span><span class="re1">$doc</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// commit the index</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$index</span><span class="sy0">-&gt;</span><span class="me1">commit</span><span class="br0">&#40;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
</ol>
</div>
<p>Pretty straightforward. You can see I have used three different static methods for adding fields to the document:</p>
<ul>
<li><strong>UnIndexed</strong>: unindexed and unstored (therefor unsearchable) but they are returned with search results. Unindexed fields usually store primary keys, timestamps or file paths.</li>
<li><strong>Text</strong>: indexed, stored and tokenized. Text fields are searchable and are returned with search hits. Titles, first and last names, cities and states, post codes and street names are all good candidates for keyword fields.</li>
<li><strong>UnStored</strong>: indexed and unstored &#8211; ideal for large texts.</li>
</ul>
<p>There are more types of fields you can use (keyword, binary) but you can read about them in the documentation.</p>
<p>Next thing you need to do is update the index every once in a while so the search hits return up-to-date information. There are two ways to get around this problem. The most obvious is to update the index every time a new post is published or an existing post is edited. Another approach would be to set up a cron job to run every now and then and rebuild the index. Which way you choose depends on many variables such as expected index size (a very large index can have few GBs in size).</p>
<p>Secondly, the index is already taken care of, so let&#8217;s search it:</p>
<div class="geshi no php">
<ol>
<li class="li1">
<div class="de1">Zend_Search_Lucene_Analysis_Analyzer<span class="sy0">::</span><span class="me2">setDefault</span><span class="br0">&#40;</span><span class="kw2">new</span> Zend_Search_Lucene_Analysis_Analyzer_Common_Utf8<span class="br0">&#40;</span><span class="br0">&#41;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">Zend_Search_Lucene<span class="sy0">::</span><span class="me2">setResultSetLimit</span><span class="br0">&#40;</span><span class="nu0">10</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// explode the search query to individual words</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$words</span>  <span class="sy0">=</span> <span class="kw3">explode</span><span class="br0">&#40;</span><span class="st0">&#39; &#39;</span><span class="sy0">,</span> <span class="kw3">urldecode</span><span class="br0">&#40;</span><span class="re1">$request</span><span class="sy0">-&gt;</span><span class="me1">getParam</span><span class="br0">&#40;</span><span class="st0">&#39;search_for&#39;</span><span class="br0">&#41;</span><span class="br0">&#41;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// start a search query and add a term for each word to it</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$query</span> <span class="sy0">=</span> <span class="kw2">new</span> Zend_Search_Lucene_Search_Query_MultiTerm<span class="br0">&#40;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="kw1">foreach</span> <span class="br0">&#40;</span><span class="re1">$words</span> <span class="kw1">as</span> <span class="re1">$w</span><span class="br0">&#41;</span> <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="re1">$query</span><span class="sy0">-&gt;</span><span class="me1">addTerm</span><span class="br0">&#40;</span><span class="kw2">new</span> Zend_Search_Lucene_Index_Term<span class="br0">&#40;</span><span class="re1">$w</span><span class="br0">&#41;</span><span class="sy0">,</span> <span class="kw2">true</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// open and query the index</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$index</span> <span class="sy0">=</span> Zend_Search_Lucene<span class="sy0">::</span><span class="me2">open</span><span class="br0">&#40;</span><span class="st0">&#39;data/posts_index&#39;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$results</span> <span class="sy0">=</span> <span class="re1">$index</span><span class="sy0">-&gt;</span><span class="me1">find</span><span class="br0">&#40;</span><span class="re1">$query</span><span class="br0">&#41;</span><span class="sy0">;</span> <span class="co1">// the search results</span></div>
</li>
</ol>
</div>
<p>That was possibly the simplest possible example of a Lucene search query. You can, however, create very complex queries with the powerful Lucene query language. You can either build queries manually in PHP or you can use Zend_Search_Lucene methods to build them. It&#8217;s so easy a baby could do it.</p>
<p>To search for posts with words &#8216;hello&#8217; and &#8216;word&#8217; in the contents field you would write this query:</p>
<pre>hello</pre>
<p>To search for a post that must contain &#8216;hello&#8217; and may contain &#8216;world&#8217;:</p>
<pre>+hello world</pre>
<p>To search for a post that must contain &#8216;hello&#8217; in the contents field and may contain &#8216;world&#8217; in the title field:</p>
<pre>+hello title:"world"</pre>
<p>And those were just basics. You can use boolean operators, wildcards, ranges and even perform a fuzzy search.</p>
]]></content:encoded>
			<wfw:commentRss>http://blog.richardknop.com/2010/03/a-simple-search-engine-implementing-zend_search_lucene/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
		</item>
		<item>
		<title>http_build_query() in PHP5</title>
		<link>http://blog.richardknop.com/2010/02/http_build_query-in-php5/</link>
		<comments>http://blog.richardknop.com/2010/02/http_build_query-in-php5/#comments</comments>
		<pubDate>Mon, 08 Feb 2010 18:59:54 +0000</pubDate>
		<dc:creator>Richard Knop</dc:creator>
				<category><![CDATA[PHP]]></category>

		<guid isPermaLink="false">http://blog.richardknop.com/?p=550</guid>
		<description><![CDATA[I can&#8217;t tell how many times I need to pass some data via GET method to another PHP script and I always forget about this neat little function so I just do it like this (like a fool):



$arr = array&#40;&#39;foo&#39; =&#62; &#39;bar&#39;,


&#160; &#160; &#160; &#160; &#160; &#160; &#160;&#39;baz&#39; =&#62; &#39;boom&#39;,


&#160; &#160; &#160; &#160; &#160; &#160; [...]]]></description>
			<content:encoded><![CDATA[<p>I can&#8217;t tell how many times I need to pass some data via GET method to another PHP script and I always forget about this neat little function so I just do it like this (like a fool):</p>
<div class="geshi no php">
<ol>
<li class="li1">
<div class="de1"><span class="re1">$arr</span> <span class="sy0">=</span> <span class="kw3">array</span><span class="br0">&#40;</span><span class="st0">&#39;foo&#39;</span> <span class="sy0">=&gt;</span> <span class="st0">&#39;bar&#39;</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="st0">&#39;baz&#39;</span> <span class="sy0">=&gt;</span> <span class="st0">&#39;boom&#39;</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="st0">&#39;cow&#39;</span> <span class="sy0">=&gt;</span> <span class="st0">&#39;milk&#39;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$query</span> <span class="sy0">=</span> <span class="kw3">array</span><span class="br0">&#40;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="kw1">foreach</span> <span class="br0">&#40;</span><span class="re1">$arr</span> <span class="kw1">as</span> <span class="re1">$k</span> <span class="sy0">=&gt;</span> <span class="re1">$v</span><span class="br0">&#41;</span> <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="re1">$query</span><span class="br0">&#91;</span><span class="br0">&#93;</span> <span class="sy0">=</span> <span class="re1">$k</span> <span class="sy0">.</span> <span class="st0">&#39;=&#39;</span> <span class="sy0">.</span> <span class="re1">$v</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$query</span> <span class="sy0">=</span> <span class="kw3">implode</span><span class="br0">&#40;</span><span class="st0">&#39;&amp;&#39;</span><span class="sy0">,</span> <span class="re1">$query</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// foo=bar&amp;baz=boom&amp;cow=milk</span></div>
</li>
</ol>
</div>
<p>When it&#8217;s so easy with the http_build_query() function:</p>
<div class="geshi no php">
<ol>
<li class="li1">
<div class="de1"><span class="re1">$query</span> <span class="sy0">=</span> http_build_query<span class="br0">&#40;</span><span class="re1">$arr</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// foo=bar&amp;baz=boom&amp;cow=milk</span></div>
</li>
</ol>
</div>
<p>This is also useful when using cURL to perform POST or GET calls.</p>
]]></content:encoded>
			<wfw:commentRss>http://blog.richardknop.com/2010/02/http_build_query-in-php5/feed/</wfw:commentRss>
		<slash:comments>2</slash:comments>
		</item>
		<item>
		<title>Poderosa: great alternative to putty</title>
		<link>http://blog.richardknop.com/2010/01/poderosa-great-alternative-to-putty/</link>
		<comments>http://blog.richardknop.com/2010/01/poderosa-great-alternative-to-putty/#comments</comments>
		<pubDate>Sat, 09 Jan 2010 22:33:38 +0000</pubDate>
		<dc:creator>Richard Knop</dc:creator>
				<category><![CDATA[Gadgets]]></category>
		<category><![CDATA[Pedorosa]]></category>

		<guid isPermaLink="false">http://blog.richardknop.com/?p=542</guid>
		<description><![CDATA[Putty is the most popular telnet/ssh client and most of you are probably using it. However, there&#8217;s one major problem I have with putty &#8211; it doesn&#8217;t remember username and password. Everytime I want to login through ssh to my server, I have to find a secret paper with my username and password (very complex [...]]]></description>
			<content:encoded><![CDATA[<p>Putty is the most popular telnet/ssh client and most of you are probably using it. However, there&#8217;s one major problem I have with putty &#8211; it doesn&#8217;t remember username and password. Everytime I want to login through ssh to my server, I have to find a secret paper with my username and password (very complex and impossible to remember -  it&#8217;s randomly generated by <a href="http://www.goodpassword.com/">this password generator</a>). And that&#8217;s quite a drag after a while.</p>
<p>So I looked for an alternative and found <a href="http://en.poderosa.org/">Pedorosa</a>. It&#8217;s more complicated than putty (plus you have to install it) but it remembers your username and password plus it has many more features you might find interesting such as multiple connections in tabs and so on.</p>
]]></content:encoded>
			<wfw:commentRss>http://blog.richardknop.com/2010/01/poderosa-great-alternative-to-putty/feed/</wfw:commentRss>
		<slash:comments>4</slash:comments>
		</item>
		<item>
		<title>Please use partials in your ZF apps</title>
		<link>http://blog.richardknop.com/2010/01/please-use-partials-in-your-zf-apps/</link>
		<comments>http://blog.richardknop.com/2010/01/please-use-partials-in-your-zf-apps/#comments</comments>
		<pubDate>Mon, 04 Jan 2010 00:49:30 +0000</pubDate>
		<dc:creator>Richard Knop</dc:creator>
				<category><![CDATA[PHP]]></category>
		<category><![CDATA[Zend Framework]]></category>

		<guid isPermaLink="false">http://blog.richardknop.com/?p=534</guid>
		<description><![CDATA[Wouldn&#8217;t you agree that using exactly the same markup in 15 views is a little bit redundant? Now imagine doing that 10 times in your application (that&#8217;s 15*10-15 which equals to 135 reduntant repetitions of the same piece of XHTML). Well, that&#8217;s the easier part. Now imagine you need to make few changes in the [...]]]></description>
			<content:encoded><![CDATA[<p>Wouldn&#8217;t you agree that using exactly the same markup in 15 views is a little bit redundant? Now imagine doing that 10 times in your application (that&#8217;s 15*10-15 which equals to 135 reduntant repetitions of the same piece of XHTML). Well, that&#8217;s the easier part. Now imagine you need to make few changes in the markup after few days. Guess what &#8211; you are going to do those worthless 135 repetitions again. And surely you might need more changes in the markup two weeks later&#8230; I could go on. There&#8217;s nothing easier than avoiding this problem in Zend Framework.</p>
<p>The solution is to use partial view helper which allows you to put the repetitive XHTML into a single file. For example, this could be your partial:</p>
<div class="geshi no php">
<ol>
<li class="li1">
<div class="de1"><span class="kw2">&lt;?php</span> <span class="co1">// saved in views/scripts/index/partials/partial.phtml ?&gt;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="sy0">&lt;</span>h3<span class="sy0">&gt;&lt;</span>?php <span class="kw3">echo</span> <span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">escape</span><span class="br0">&#40;</span><span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">heading</span><span class="br0">&#41;</span><span class="sy0">;</span> ?<span class="sy0">&gt;&lt;/</span>h3<span class="sy0">&gt;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="sy0">&lt;</span>p<span class="sy0">&gt;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; Lorem ipsum dolor sit amet<span class="sy0">,</span> consectetur adipiscing elit<span class="sy0">.</span> </div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; Mauris porta<span class="sy0">,</span> sapien at accumsan venenatis<span class="sy0">,</span> neque velit </div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; sodales augue<span class="sy0">,</span> sit amet posuere odio enim quis risus<span class="sy0">.</span> </div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; Aliquam semper<span class="sy0">,</span> ipsum porttitor ultricies bibendum<span class="sy0">,</span> sem </div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; sapien tincidunt purus<span class="sy0">,</span> eget sollicitudin felis eros </div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; fermentum felis<span class="sy0">.</span> Praesent vehicula varius est at semper<span class="sy0">.</span> </div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; Nam nulla augue<span class="sy0">,</span> fermentum in varius vel<span class="sy0">,</span> tincidunt non </div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; nibh<span class="sy0">.</span> In vitae neque vitae metus dignissim hendrerit<span class="sy0">.</span> </div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; Nulla eget massa nec sapien tempor ultricies a et tellus<span class="sy0">.</span> </div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; Sed imperdiet<span class="sy0">,</span> risus quis vehicula ornare<span class="sy0">,</span> justo lorem </div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; iaculis sapien<span class="sy0">,</span> id semper massa nisi eu purus<span class="sy0">.</span> </div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; Suspendisse sed urna eu risus rhoncus bibendum<span class="sy0">.</span> Cras </div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; feugiat consectetur nisi id dictum<span class="sy0">.</span> Pellentesque quis </div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; mauris a risus dapibus dictum nec sed nisl<span class="sy0">.</span></div>
</li>
<li class="li1">
<div class="de1"><span class="sy0">&lt;/</span>p<span class="sy0">&gt;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="sy0">&lt;</span>ul<span class="sy0">&gt;</span></div>
</li>
<li class="li1">
<div class="de1">    <span class="sy0">&lt;</span>li<span class="sy0">&gt;</span>List Item <span class="nu0">1</span><span class="sy0">:</span> <span class="kw2">&lt;?php</span> <span class="kw3">echo</span> <span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">escape</span><span class="br0">&#40;</span><span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">li1</span><span class="br0">&#41;</span><span class="sy0">;</span> ?<span class="sy0">&gt;&lt;/</span>li<span class="sy0">&gt;</span></div>
</li>
<li class="li1">
<div class="de1">    <span class="sy0">&lt;</span>li<span class="sy0">&gt;</span>List Item <span class="nu0">2</span><span class="sy0">:</span> <span class="kw2">&lt;?php</span> <span class="kw3">echo</span> <span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">escape</span><span class="br0">&#40;</span><span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">li2</span><span class="br0">&#41;</span><span class="sy0">;</span> ?<span class="sy0">&gt;&lt;/</span>li<span class="sy0">&gt;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="sy0">&lt;</span>li<span class="sy0">&gt;</span>List Item <span class="nu0">3</span><span class="sy0">:</span> <span class="kw2">&lt;?php</span> <span class="kw3">echo</span> <span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">escape</span><span class="br0">&#40;</span><span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">li3</span><span class="br0">&#41;</span><span class="sy0">;</span> ?<span class="sy0">&gt;&lt;/</span>li<span class="sy0">&gt;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="sy0">&lt;/</span>ul<span class="sy0">&gt;</span></div>
</li>
</ol>
</div>
<p>And this is how you would include it in all views where the same piece of markup occurs:</p>
<div class="geshi no php">
<ol>
<li class="li1">
<div class="de1"><span class="kw2">&lt;?php</span> <span class="kw3">echo</span> <span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">partial</span><span class="br0">&#40;</span><span class="st0">&#39;index/partials/partial.phtml&#39;</span><span class="sy0">,</span> <span class="kw3">array</span><span class="br0">&#40;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="st0">&#39;heading&#39;</span> <span class="sy0">=&gt;</span> <span class="st0">&#39;Lorem Ipsum&#39;</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">    <span class="st0">&#39;li1&#39;</span> <span class="sy0">=&gt;</span> <span class="st0">&#39;Hello&#39;</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">    <span class="st0">&#39;li2&#39;</span> <span class="sy0">=&gt;</span> <span class="st0">&#39;World&#39;</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="st0">&#39;li3&#39;</span> <span class="sy0">=&gt;</span> <span class="st0">&#39;!!!&#39;</span><span class="br0">&#41;</span><span class="br0">&#41;</span><span class="sy0">;</span> <span class="kw2">?&gt;</span></div>
</li>
</ol>
</div>
<p>It&#8217;s really easy and it saves a huge amount of time both to you and to a developer that might work on your application in the future so please, all of you Zend Framework developers, use partial helpers wherever there is a repetitive XHTML markup in your application.</p>
]]></content:encoded>
			<wfw:commentRss>http://blog.richardknop.com/2010/01/please-use-partials-in-your-zf-apps/feed/</wfw:commentRss>
		<slash:comments>0</slash:comments>
		</item>
		<item>
		<title>Making Zend_Captcha_Image easier to read</title>
		<link>http://blog.richardknop.com/2009/12/making-zend_captcha_image-easier-to-read/</link>
		<comments>http://blog.richardknop.com/2009/12/making-zend_captcha_image-easier-to-read/#comments</comments>
		<pubDate>Tue, 22 Dec 2009 18:58:25 +0000</pubDate>
		<dc:creator>Richard Knop</dc:creator>
				<category><![CDATA[PHP]]></category>
		<category><![CDATA[Zend Framework]]></category>
		<category><![CDATA[Zend_Captcha_Image]]></category>

		<guid isPermaLink="false">http://blog.richardknop.com/?p=530</guid>
		<description><![CDATA[Sometimes people will complain that the captcha is too difficult to read and they have to reload the page in order to be able to pass the captcha test. If you are not willing to say goodbye to the very flexible Zend_Captcha_Image there are only two ways how to make it easier to read:

Use different [...]]]></description>
			<content:encoded><![CDATA[<p>Sometimes people will complain that the captcha is too difficult to read and they have to reload the page in order to be able to pass the captcha test. If you are not willing to say goodbye to the very flexible Zend_Captcha_Image there are only two ways how to make it easier to read:</p>
<ol>
<li>Use different font (I have found that Arial is sometimes hard to read, a good replacement seems to be LBRITED.TTF).</li>
<li>Set lower dot and line noise level.</li>
</ol>
<p>You can use &#8220;dotNoiseLevel&#8221; and &#8220;lineNoiseLevel&#8221; to tune down the captcha noise (and surpisingly this is not mentioned in the Zend Framework documentation):</p>
<div class="geshi no php">
<ol>
<li class="li1">
<div class="de1"><span class="re1">$captcha</span> <span class="sy0">=</span> <span class="kw2">new</span> Zend_Form_Element_Captcha<span class="br0">&#40;</span><span class="st0">&#39;captcha&#39;</span><span class="sy0">,</span> <span class="kw3">array</span><span class="br0">&#40;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="st0">&#39;label&#39;</span> <span class="sy0">=&gt;</span> <span class="st0">&#39;Captcha&#39;</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="st0">&#39;helper&#39;</span> <span class="sy0">=&gt;</span> <span class="kw2">null</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="st0">&#39;captcha&#39;</span> <span class="sy0">=&gt;</span> <span class="kw3">array</span><span class="br0">&#40;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="st0">&#39;captcha&#39;</span> <span class="sy0">=&gt;</span> <span class="st0">&#39;Image&#39;</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="st0">&#39;wordLen&#39;</span> <span class="sy0">=&gt;</span> <span class="nu0">5</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="st0">&#39;timeout&#39;</span> <span class="sy0">=&gt;</span> <span class="nu0">300</span><span class="sy0">,</span> <span class="co1">// 5 minutes timeout</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="st0">&#39;font&#39;</span> <span class="sy0">=&gt;</span> <span class="st0">&#39;fonts/LBRITED.TTF&#39;</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="st0">&#39;fontSize&#39;</span> <span class="sy0">=&gt;</span> <span class="nu0">20</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="st0">&#39;width&#39;</span> <span class="sy0">=&gt;</span> <span class="nu0">100</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="st0">&#39;height&#39;</span> <span class="sy0">=&gt;</span> <span class="nu0">60</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="st0">&#39;imgDir&#39;</span> <span class="sy0">=&gt;</span> <span class="st0">&#39;images/captcha/&#39;</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="st0">&#39;imgUrl&#39;</span> <span class="sy0">=&gt;</span> <span class="st0">&#39;/images/captcha/&#39;</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="st0">&#39;dotNoiseLevel&#39;</span> <span class="sy0">=&gt;</span> <span class="nu0">15</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="st0">&#39;lineNoiseLevel&#39;</span> <span class="sy0">=&gt;</span> <span class="nu0">1</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#41;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
</ol>
</div>
<p>Above I went over the top perhaps. Nevertheless, you must be able to find a compromise so that the users will be happy and the security side of your website won&#8217;t suffer too much.</p>
]]></content:encoded>
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		<slash:comments>1</slash:comments>
		</item>
		<item>
		<title>Caching with Zend_Cache</title>
		<link>http://blog.richardknop.com/2009/12/caching-with-zend_cache/</link>
		<comments>http://blog.richardknop.com/2009/12/caching-with-zend_cache/#comments</comments>
		<pubDate>Mon, 21 Dec 2009 14:21:42 +0000</pubDate>
		<dc:creator>Richard Knop</dc:creator>
				<category><![CDATA[MySQL]]></category>
		<category><![CDATA[PHP]]></category>
		<category><![CDATA[Zend Framework]]></category>

		<guid isPermaLink="false">http://blog.richardknop.com/?p=523</guid>
		<description><![CDATA[Caching with PHP is the best way to speed up your application and it&#8217;s quite easy thanks to native PHP modules such as APC or output buffering control. It&#8217;s even much much easier when you are using the Zend Framework as it contains a native class just for caching &#8211; Zend_Cache. To use the Zend_Cache [...]]]></description>
			<content:encoded><![CDATA[<p>Caching with PHP is the best way to speed up your application and it&#8217;s quite easy thanks to native PHP modules such as <a href="http://php.net/manual/en/book.apc.php">APC</a> or <a href="http://php.net/manual/en/book.outcontrol.php">output buffering control</a>. It&#8217;s even much much easier when you are using the Zend Framework as it contains a native class just for caching &#8211; <a href="http://framework.zend.com/manual/en/zend.cache.html">Zend_Cache</a>. To use the Zend_Cache you must first initialize it in the bootstrap and add it to the registry so you can access it easily in controllers, I do it like this:</p>
<div class="geshi no php">
<ol>
<li class="li1">
<div class="de1">protected <span class="kw2">function</span> _initCache<span class="br0">&#40;</span><span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="re1">$frontend</span> <span class="sy0">=</span> <span class="kw3">array</span><span class="br0">&#40;</span><span class="st0">&#39;lifetime&#39;</span> <span class="sy0">=&gt;</span> <span class="nu0">7200</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="st0">&#39;automatic_seralization&#39;</span> <span class="sy0">=&gt;</span> <span class="kw2">true</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="co1">// where are we going to stored the cached files?</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="re1">$backend</span> <span class="sy0">=</span> <span class="kw3">array</span><span class="br0">&#40;</span><span class="st0">&#39;cache_dir&#39;</span> <span class="sy0">=&gt;</span> <span class="st0">&#39;cache&#39;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">cache</span> <span class="sy0">=</span> Zend_Cache<span class="sy0">::</span><span class="me2">factory</span><span class="br0">&#40;</span><span class="st0">&#39;core&#39;</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="st0">&#39;File&#39;</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="re1">$frontend</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="re1">$backend</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">protected <span class="kw2">function</span> _initRegistry<span class="br0">&#40;</span><span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">registry</span> <span class="sy0">=</span> Zend_Registry<span class="sy0">::</span><span class="me2">getInstance</span><span class="br0">&#40;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">registry</span><span class="sy0">-&gt;</span><span class="me1">cache</span> <span class="sy0">=</span> <span class="re1">$this</span><span class="sy0">-&gt;</span><span class="me1">cache</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="co1">// I store much more in the registry, of course</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="co1">// for instance, configuration and db adapter</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#125;</span></div>
</li>
</ol>
</div>
<p>The frontend and the backend adapters can take much more arguments, read the documentation to learn all possible options. I initialized the Zend_Cache object with the factory method. First argument means that we want to use the Zend_Cache_Core frontend which is the core of the Zend_Cache module. The second argument is the backend we want to use the Zend_Cache_Backend_File backend or that we want to store cached data as files in a specific directory. The other two parameters are frontend and backend options.</p>
<p>Now we can easily access the cache object in controllers or models:</p>
<div class="geshi no php">
<ol>
<li class="li1">
<div class="de1"><span class="re1">$cache</span> <span class="sy0">=</span> Zend_Registry<span class="sy0">::</span><span class="me2">get</span><span class="br0">&#40;</span><span class="st0">&#39;cache&#39;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// does the cache contain data we are looking for?</span></div>
</li>
<li class="li1">
<div class="de1"><span class="kw1">if</span> <span class="br0">&#40;</span><span class="sy0">!</span><span class="re1">$result</span> <span class="sy0">=</span> <span class="re1">$cache</span><span class="sy0">-&gt;</span><span class="me1">load</span><span class="br0">&#40;</span><span class="st0">&#39;myUniqueId&#39;</span><span class="br0">&#41;</span><span class="br0">&#41;</span> <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="co1">// if not let&#39;s cache the data</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="co1">// here I use only a random array but in a real application</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="co1">// you would probably cache some database entries</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="re1">$data</span> <span class="sy0">=</span> <span class="kw3">array</span><span class="br0">&#40;</span><span class="st0">&#39;John Doe&#39;</span><span class="sy0">,</span> <span class="st0">&#39;Jane Doe&#39;</span><span class="sy0">,</span> <span class="st0">&#39;Baby Doe&#39;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="co1">// besides unique cache id you can use tags to categorize data</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="re1">$cache</span><span class="sy0">-&gt;</span><span class="me1">save</span><span class="br0">&#40;</span><span class="re1">$data</span><span class="sy0">,</span> <span class="st0">&#39;myUniqueId&#39;</span><span class="sy0">,</span> <span class="kw3">array</span><span class="br0">&#40;</span><span class="st0">&#39;tag1&#39;</span><span class="sy0">,</span> <span class="st0">&#39;tag2&#39;</span><span class="br0">&#41;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#125;</span> <span class="kw1">else</span> <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="co1">// dump the cached data</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw3">var_dump</span><span class="br0">&#40;</span><span class="re1">$result</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#125;</span></div>
</li>
</ol>
</div>
<p>That was easy, wasn&#8217;t it?</p>
<h3>Cleaning the cache</h3>
<p>You will surely also want to remove cached files at some point in your application:</p>
<div class="geshi no php">
<ol>
<li class="li1">
<div class="de1"><span class="co1">// clean all cached files</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$cache</span><span class="sy0">-&gt;</span><span class="me1">clean</span><span class="br0">&#40;</span>Zend_Cache<span class="sy0">::</span> <span class="me2">CLEANING_MODE_ALL</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// clean only outdated cached files</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$cache</span><span class="sy0">-&gt;</span><span class="me1">clean</span><span class="br0">&#40;</span>Zend_Cache<span class="sy0">::</span><span class="me2">CLEANING_MODE_OLD</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// remove a particular cache id</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$cache</span><span class="sy0">-&gt;</span><span class="me1">remove</span><span class="br0">&#40;</span><span class="st0">&#39;myUniqueId&#39;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// remove records tagged as &quot;tag1&quot; AND &quot;tag2&quot;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$cache</span><span class="sy0">-&gt;</span><span class="me1">clean</span><span class="br0">&#40;</span>Zend_Cache<span class="sy0">::</span><span class="me2">CLEANING_MODE_MATCHING_TAG</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span class="kw3">array</span><span class="br0">&#40;</span><span class="st0">&#39;tag1&#39;</span><span class="sy0">,</span> <span class="st0">&#39;tag2&#39;</span><span class="br0">&#41;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// remove records tagged as &quot;tag1&quot; OR :tag2&quot;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$cache</span><span class="sy0">-&gt;</span><span class="me1">clean</span><span class="br0">&#40;</span>Zend_Cache<span class="sy0">::</span><span class="me2">CLEANING_MODE_MATCHING_ANY_TAG</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span class="kw3">array</span><span class="br0">&#40;</span><span class="st0">&#39;tag1&#39;</span><span class="sy0">,</span> <span class="st0">&#39;tag2&#39;</span><span class="br0">&#41;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co1">// remove records NOT tagged as &quot;tag1&quot; or &quot;tag2&quot;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="re1">$cache</span><span class="sy0">-&gt;</span><span class="me1">clean</span><span class="br0">&#40;</span>Zend_Cache<span class="sy0">::</span><span class="me2">CLEANING_MODE_NOT_MATCHING_ANY_TAG</span><span class="sy0">,</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span class="kw3">array</span><span class="br0">&#40;</span><span class="st0">&#39;tag1&#39;</span><span class="sy0">,</span> <span class="st0">&#39;tag2&#39;</span><span class="br0">&#41;</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
</ol>
</div>
<p>That&#8217;s it for today and, by the way, Merry Christmas <img src='http://blog.richardknop.com/wp-includes/images/smilies/icon_smile.gif' alt=':)' class='wp-smiley' /> </p>
]]></content:encoded>
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		</item>
		<item>
		<title>500 Internal Server Error</title>
		<link>http://blog.richardknop.com/2009/12/500-internal-server-error/</link>
		<comments>http://blog.richardknop.com/2009/12/500-internal-server-error/#comments</comments>
		<pubDate>Tue, 08 Dec 2009 00:19:16 +0000</pubDate>
		<dc:creator>Richard Knop</dc:creator>
				<category><![CDATA[Uncategorized]]></category>

		<guid isPermaLink="false">http://blog.richardknop.com/?p=519</guid>
		<description><![CDATA[I have recently switched web hosting provider and had to move my personal website and blog over to the new one. I have encountered a simple problem when trying to get my personal website to work (it&#8217;s a Zend Framework application). I got the 500 Internal Server Error:

The problem lied in this .htaccess rule:
php_flag magic_quotes_gpc [...]]]></description>
			<content:encoded><![CDATA[<p>I have recently switched web hosting provider and had to move my personal website and blog over to the new one. I have encountered a simple problem when trying to get my personal website to work (it&#8217;s a Zend Framework application). I got the 500 Internal Server Error:</p>
<p><img class="alignnone size-full wp-image-520" title="500 Internal Server Error" src="http://blog.richardknop.com/wp-content/uploads/2009/12/500-internal-server-error.gif" alt="500 Internal Server Error" width="571" height="327" /></p>
<p>The problem lied in this .htaccess rule:</p>
<pre>php_flag magic_quotes_gpc off</pre>
<p>So I just commented the line and the error went away.</p>
<p>The line&#8217;s purpose was to make sure magic quotes are turned off in PHP.  You can use it if your web host supports it, if not just add this to your bootstrap file:</p>
<div class="geshi no php">
<ol>
<li class="li1">
<div class="de1">protected <span class="kw2">function</span> _initGetRidOfMagicQuotes<span class="br0">&#40;</span><span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">    <span class="kw1">if</span> <span class="br0">&#40;</span><span class="kw3">get_magic_quotes_gpc</span><span class="br0">&#40;</span><span class="br0">&#41;</span><span class="br0">&#41;</span> <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">        <span class="kw2">function</span> stripslashes_deep<span class="br0">&#40;</span><span class="re1">$value</span><span class="br0">&#41;</span> <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">            <span class="re1">$value</span> <span class="sy0">=</span> <span class="kw3">is_array</span><span class="br0">&#40;</span><span class="re1">$value</span><span class="br0">&#41;</span> ?</div>
</li>
<li class="li1">
<div class="de1">            <span class="kw3">array_map</span><span class="br0">&#40;</span><span class="st0">&#39;stripslashes_deep&#39;</span><span class="sy0">,</span> <span class="re1">$value</span><span class="br0">&#41;</span> <span class="sy0">:</span></div>
</li>
<li class="li1">
<div class="de1">            <span class="kw3">stripslashes</span><span class="br0">&#40;</span><span class="re1">$value</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">            <span class="kw1">return</span> <span class="re1">$value</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">        <span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">        <span class="re1">$_POST</span> <span class="sy0">=</span> <span class="kw3">array_map</span><span class="br0">&#40;</span><span class="st0">&#39;stripslashes_deep&#39;</span><span class="sy0">,</span> <span class="re1">$_POST</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">        <span class="re1">$_GET</span> <span class="sy0">=</span> <span class="kw3">array_map</span><span class="br0">&#40;</span><span class="st0">&#39;stripslashes_deep&#39;</span><span class="sy0">,</span> <span class="re1">$_GET</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">        <span class="re1">$_COOKIE</span> <span class="sy0">=</span> <span class="kw3">array_map</span><span class="br0">&#40;</span><span class="st0">&#39;stripslashes_deep&#39;</span><span class="sy0">,</span> <span class="re1">$_COOKIE</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;       <span class="re1">$_REQUEST</span> <span class="sy0">=</span> <span class="kw3">array_map</span><span class="br0">&#40;</span><span class="st0">&#39;stripslashes_deep&#39;</span><span class="sy0">,</span> <span class="re1">$_REQUEST</span><span class="br0">&#41;</span><span class="sy0">;</span></div>
</li>
<li class="li1">
<div class="de1">   &nbsp;<span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#125;</span></div>
</li>
</ol>
</div>
]]></content:encoded>
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		<item>
		<title>Perceptron in ANSI C</title>
		<link>http://blog.richardknop.com/2009/11/perceptron-in-ansi-c/</link>
		<comments>http://blog.richardknop.com/2009/11/perceptron-in-ansi-c/#comments</comments>
		<pubDate>Sun, 08 Nov 2009 14:49:11 +0000</pubDate>
		<dc:creator>Richard Knop</dc:creator>
				<category><![CDATA[Uncategorized]]></category>

		<guid isPermaLink="false">http://blog.richardknop.com/?p=508</guid>
		<description><![CDATA[One of my school assignments was to write a simple ANSI C Perceptron algorithm that would be able to separate points on a two dimensional plane into two sets (-1 and 1). Fortunately, while reading a Wikipedia article about Perceptron, I have found a great external link at the bottom of it: C# implementation of [...]]]></description>
			<content:encoded><![CDATA[<p>One of my school assignments was to write a simple ANSI C Perceptron algorithm that would be able to separate points on a two dimensional plane into two sets (-1 and 1). Fortunately, while reading a <a href="http://en.wikipedia.org/wiki/Perceptron">Wikipedia article about Perceptron</a>, I have found a great external link at the bottom of it: <a href="http://dynamicnotions.blogspot.com/2008/09/single-layer-perceptron.html">C# implementation of a Perceptron</a>. This helped me a lot to understand how the Perceptron works and how to implement it programatically.</p>
<p>What I have done is rewrite the code snippet from <a href="http://dynamicnotions.blogspot.com/">John Wakefield</a> in the C language. Instead of data type double I used two integer arrays (one denotes x and the other one y coordinates of points from a training set). Plus I have added a simple code do draw a nice graph of the training set and its linear separation. I used <a href="http://www.libgd.org/Main_Page">GD</a> to draw the image. I would also like to thank <a href="http://stackoverflow.com/users/97160/amro">Amro</a> for helping me finish this algorithm.</p>
<p><img class="alignnone size-full wp-image-507" title="Perceptron linear separation" src="http://blog.richardknop.com/wp-content/uploads/2009/11/training.png" alt="Perceptron linear separation" width="600" height="600" /></p>
<p>Here&#8217;s the entire code:</p>
<div class="geshi no c">
<ol>
<li class="li1">
<div class="de1"><span class="co2">#include &lt;stdio.h&gt;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co2">#include &lt;stdlib.h&gt;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co2">#include &lt;gd.h&gt;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co2">#include &lt;math.h&gt;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1"><span class="co2">#define NUMEL &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;208</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co2">#define LEARNING_RATE &nbsp; &nbsp;0.1</span></div>
</li>
<li class="li1">
<div class="de1"><span class="co2">#define MAX_ITERATION &nbsp; &nbsp;100</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1"><span class="kw4">float</span> randomFloat<span class="br0">&#40;</span><span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw4">float</span> r <span class="sy0">=</span> <span class="br0">&#40;</span><span class="kw4">float</span><span class="br0">&#41;</span>rand<span class="br0">&#40;</span><span class="br0">&#41;</span> <span class="sy0">/</span> <span class="br0">&#40;</span><span class="kw4">float</span><span class="br0">&#41;</span>RAND_MAX;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw1">return</span> r;</div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1"><span class="kw4">int</span> calculateOutput<span class="br0">&#40;</span><span class="kw4">float</span> weights<span class="br0">&#91;</span><span class="br0">&#93;</span>, <span class="kw4">float</span> x, <span class="kw4">float</span> y<span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw4">float</span> sum <span class="sy0">=</span> x <span class="sy0">*</span> weights<span class="br0">&#91;</span><span class="nu0">0</span><span class="br0">&#93;</span> <span class="sy0">+</span> y <span class="sy0">*</span> weights<span class="br0">&#91;</span><span class="nu0">1</span><span class="br0">&#93;</span> <span class="sy0">+</span> weights<span class="br0">&#91;</span><span class="nu0">2</span><span class="br0">&#93;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw1">return</span> <span class="br0">&#40;</span>sum &gt;<span class="sy0">=</span> <span class="nu0">0</span><span class="br0">&#41;</span> ? <span class="nu0">1</span> <span class="sy0">:</span> <span class="nu0">-1</span>;</div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1"><span class="kw4">int</span> main<span class="br0">&#40;</span><span class="kw4">int</span> argc, <span class="kw4">char</span> <span class="sy0">*</span>argv<span class="br0">&#91;</span><span class="br0">&#93;</span><span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; srand<span class="br0">&#40;</span>time<span class="br0">&#40;</span><span class="kw2">NULL</span><span class="br0">&#41;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw4">float</span> x<span class="br0">&#91;</span>NUMEL<span class="br0">&#93;</span>, y<span class="br0">&#91;</span>NUMEL<span class="br0">&#93;</span>, weights<span class="br0">&#91;</span><span class="nu0">3</span><span class="br0">&#93;</span>, localError, globalError, a, b;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw4">int</span> outputs<span class="br0">&#91;</span>NUMEL<span class="br0">&#93;</span>, patternCount, i, p, iteration, output;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; FILE <span class="sy0">*</span>fp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw1">if</span> <span class="br0">&#40;</span><span class="br0">&#40;</span>fp <span class="sy0">=</span> fopen<span class="br0">&#40;</span><span class="st0">&quot;training-set.txt&quot;</span>, <span class="st0">&quot;r&quot;</span><span class="br0">&#41;</span><span class="br0">&#41;</span> <span class="sy0">==</span> <span class="kw2">NULL</span><span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="kw3">printf</span><span class="br0">&#40;</span><span class="st0">&quot;Cannot open file.<span class="es0">\n</span>&quot;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; exit<span class="br0">&#40;</span><span class="nu0">1</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; i <span class="sy0">=</span> <span class="nu0">0</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw1">while</span> <span class="br0">&#40;</span>fscanf<span class="br0">&#40;</span>fp, <span class="st0">&quot;%f %f %d&quot;</span>, <span class="sy0">&amp;</span>x<span class="br0">&#91;</span>i<span class="br0">&#93;</span>, <span class="sy0">&amp;</span>y<span class="br0">&#91;</span>i<span class="br0">&#93;</span>, <span class="sy0">&amp;</span>outputs<span class="br0">&#91;</span>i<span class="br0">&#93;</span><span class="br0">&#41;</span> <span class="sy0">!=</span> EOF<span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="kw1">if</span> <span class="br0">&#40;</span>outputs<span class="br0">&#91;</span>i<span class="br0">&#93;</span> <span class="sy0">==</span> <span class="nu0">0</span><span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; outputs<span class="br0">&#91;</span>i<span class="br0">&#93;</span> <span class="sy0">=</span> <span class="nu0">-1</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="kw3">printf</span><span class="br0">&#40;</span><span class="st0">&quot;%.4f %.4f %d<span class="es0">\n</span>&quot;</span>, x<span class="br0">&#91;</span>i<span class="br0">&#93;</span>, y<span class="br0">&#91;</span>i<span class="br0">&#93;</span>, outputs<span class="br0">&#91;</span>i<span class="br0">&#93;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; i<span class="sy0">++</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; patternCount <span class="sy0">=</span> i;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; system<span class="br0">&#40;</span><span class="st0">&quot;PAUSE&quot;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; weights<span class="br0">&#91;</span><span class="nu0">0</span><span class="br0">&#93;</span> <span class="sy0">=</span> randomFloat<span class="br0">&#40;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; weights<span class="br0">&#91;</span><span class="nu0">1</span><span class="br0">&#93;</span> <span class="sy0">=</span> randomFloat<span class="br0">&#40;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; weights<span class="br0">&#91;</span><span class="nu0">2</span><span class="br0">&#93;</span> <span class="sy0">=</span> randomFloat<span class="br0">&#40;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; iteration <span class="sy0">=</span> <span class="nu0">0</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw1">do</span> <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; iteration<span class="sy0">++</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; globalError <span class="sy0">=</span> <span class="nu0">0</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="kw1">for</span> <span class="br0">&#40;</span>p <span class="sy0">=</span> <span class="nu0">0</span>; p &lt; patternCount; p<span class="sy0">++</span><span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; output <span class="sy0">=</span> calculateOutput<span class="br0">&#40;</span>weights, x<span class="br0">&#91;</span>p<span class="br0">&#93;</span>, y<span class="br0">&#91;</span>p<span class="br0">&#93;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; localError <span class="sy0">=</span> outputs<span class="br0">&#91;</span>p<span class="br0">&#93;</span> <span class="sy0">-</span> output;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span class="co1">// Update weights.</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; weights<span class="br0">&#91;</span><span class="nu0">0</span><span class="br0">&#93;</span> <span class="sy0">+=</span> LEARNING_RATE <span class="sy0">*</span> localError <span class="sy0">*</span> x<span class="br0">&#91;</span>p<span class="br0">&#93;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; weights<span class="br0">&#91;</span><span class="nu0">1</span><span class="br0">&#93;</span> <span class="sy0">+=</span> LEARNING_RATE <span class="sy0">*</span> localError <span class="sy0">*</span> y<span class="br0">&#91;</span>p<span class="br0">&#93;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; weights<span class="br0">&#91;</span><span class="nu0">2</span><span class="br0">&#93;</span> <span class="sy0">+=</span> LEARNING_RATE <span class="sy0">*</span> localError;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; globalError <span class="sy0">+=</span> <span class="br0">&#40;</span>localError <span class="sy0">*</span> localError<span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="coMULTI">/* Root Mean Squared Error */</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="kw3">printf</span><span class="br0">&#40;</span><span class="st0">&quot;Iteration %d : RMSE = %.4f<span class="es0">\n</span>&quot;</span>, iteration,</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;sqrt<span class="br0">&#40;</span>globalError <span class="sy0">/</span> patternCount<span class="br0">&#41;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="br0">&#125;</span> <span class="kw1">while</span> <span class="br0">&#40;</span>globalError <span class="sy0">!=</span> <span class="nu0">0</span> <span class="sy0">&amp;&amp;</span> iteration &lt;<span class="sy0">=</span> MAX_ITERATION<span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="co1">// Display network generalisation.</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw3">printf</span><span class="br0">&#40;</span><span class="st0">&quot;X &nbsp; &nbsp; &nbsp; Y &nbsp; &nbsp; Output<span class="es0">\n</span>&quot;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw4">float</span> j, k;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw1">for</span> <span class="br0">&#40;</span>j <span class="sy0">=</span> <span class="nu0">-1</span>; j &lt;<span class="sy0">=</span> <span class="nu0">1</span>; j <span class="sy0">+=</span> .<span class="nu0">5</span><span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="kw1">for</span> <span class="br0">&#40;</span>j <span class="sy0">=</span> <span class="nu0">-1</span>; j &lt;<span class="sy0">=</span> <span class="nu0">1</span>; j <span class="sy0">+=</span> .<span class="nu0">5</span><span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span class="co1">// Calculate output.</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span class="kw4">int</span> output <span class="sy0">=</span> calculateOutput<span class="br0">&#40;</span>weights, j, k<span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <span class="kw3">printf</span><span class="br0">&#40;</span><span class="st0">&quot;%.4f %.4f %s<span class="es0">\n</span>&quot;</span>, j, k, <span class="br0">&#40;</span>output <span class="sy0">==</span> <span class="nu0">1</span><span class="br0">&#41;</span> ? <span class="st0">&quot;Blue&quot;</span> <span class="sy0">:</span> <span class="st0">&quot;Red&quot;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; <span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="co1">// Display modified weights.</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw3">printf</span><span class="br0">&#40;</span><span class="st0">&quot;Modified weights: %.2f %.2f<span class="es0">\n</span>&quot;</span>, weights<span class="br0">&#91;</span><span class="nu0">0</span><span class="br0">&#93;</span>, weights<span class="br0">&#91;</span><span class="nu0">1</span><span class="br0">&#93;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="co1">// Create image representation.</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; gdImagePtr im;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; im <span class="sy0">=</span> gdImageCreateTrueColor<span class="br0">&#40;</span><span class="nu0">600</span>, <span class="nu0">600</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw1">if</span> <span class="br0">&#40;</span>im <span class="sy0">!=</span> <span class="nu0">0</span><span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="co1">// Allocate colors.</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw4">int</span> white <span class="sy0">=</span> gdImageColorAllocate<span class="br0">&#40;</span>im, <span class="nu0">255</span>, <span class="nu0">255</span>, <span class="nu0">255</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw4">int</span> lightGrey <span class="sy0">=</span> gdImageColorAllocate<span class="br0">&#40;</span>im, <span class="nu0">220</span>, <span class="nu0">220</span>, <span class="nu0">220</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw4">int</span> black <span class="sy0">=</span> gdImageColorAllocate<span class="br0">&#40;</span>im, <span class="nu0">0</span>, <span class="nu0">0</span>, <span class="nu0">0</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw4">int</span> blue <span class="sy0">=</span> gdImageColorAllocate<span class="br0">&#40;</span>im, <span class="nu0">0</span>, <span class="nu0">0</span>, <span class="nu0">255</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw4">int</span> red <span class="sy0">=</span> gdImageColorAllocate<span class="br0">&#40;</span>im, <span class="nu0">255</span>, <span class="nu0">0</span>, <span class="nu0">0</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw4">int</span> green <span class="sy0">=</span> gdImageColorAllocate<span class="br0">&#40;</span>im, <span class="nu0">0</span>, <span class="nu0">200</span>, <span class="nu0">50</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="co1">// White flood fill.</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;gdImageFill<span class="br0">&#40;</span>im, <span class="nu0">0</span>, <span class="nu0">0</span>, lightGrey<span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="co1">// Points.</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw4">float</span> cx, cy;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw1">for</span> <span class="br0">&#40;</span>i <span class="sy0">=</span> <span class="nu0">0</span>; i &lt; patternCount; i<span class="sy0">++</span><span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="co1">// Calculate output.</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw4">int</span> output <span class="sy0">=</span> calculateOutput<span class="br0">&#40;</span>weights, x<span class="br0">&#91;</span>i<span class="br0">&#93;</span>, y<span class="br0">&#91;</span>i<span class="br0">&#93;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;cx <span class="sy0">=</span> floor<span class="br0">&#40;</span><span class="nu0">300</span> <span class="sy0">+</span> <span class="nu0">30</span><span class="sy0">*</span>x<span class="br0">&#91;</span>i<span class="br0">&#93;</span> <span class="sy0">+</span> <span class="nu0">0.5</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;cy <span class="sy0">=</span> floor<span class="br0">&#40;</span><span class="nu0">300</span> <span class="sy0">-</span> <span class="nu0">30</span><span class="sy0">*</span>y<span class="br0">&#91;</span>i<span class="br0">&#93;</span> <span class="sy0">+</span> <span class="nu0">0.5</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw4">int</span> color <span class="sy0">=</span> <span class="br0">&#40;</span>output <span class="sy0">==</span> <span class="nu0">1</span><span class="br0">&#41;</span> ? blue <span class="sy0">:</span> red;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;gdImageFilledEllipse<span class="br0">&#40;</span>im, <span class="br0">&#40;</span><span class="kw4">int</span><span class="br0">&#41;</span>cx, <span class="br0">&#40;</span><span class="kw4">int</span><span class="br0">&#41;</span>cy, <span class="nu0">5</span>, <span class="nu0">5</span>, color<span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="co1">// Linear separation</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;a <span class="sy0">=</span> <span class="sy0">-</span>weights<span class="br0">&#91;</span><span class="nu0">0</span><span class="br0">&#93;</span> <span class="sy0">/</span> weights<span class="br0">&#91;</span><span class="nu0">1</span><span class="br0">&#93;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;b <span class="sy0">=</span> <span class="sy0">-</span>weights<span class="br0">&#91;</span><span class="nu0">2</span><span class="br0">&#93;</span> <span class="sy0">/</span> weights<span class="br0">&#91;</span><span class="nu0">1</span><span class="br0">&#93;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw3">printf</span><span class="br0">&#40;</span><span class="st0">&quot;Decision boundary (line) equation: y = %.4fx + %.4f<span class="es0">\n</span>&quot;</span>, a, b<span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="co1">// x = -10 =&gt; y = -10a+b</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="co1">// x = 10 =&gt; y = 10*a + b</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;gdImageLine<span class="br0">&#40;</span>im, <span class="nu0">0</span>, <span class="br0">&#40;</span><span class="kw4">int</span><span class="br0">&#41;</span><span class="br0">&#40;</span><span class="nu0">300</span> <span class="sy0">+</span> <span class="nu0">300</span><span class="sy0">*</span>a <span class="sy0">-</span> <span class="nu0">30</span><span class="sy0">*</span>b<span class="br0">&#41;</span>, <span class="nu0">600</span>, <span class="br0">&#40;</span><span class="nu0">300</span> <span class="sy0">-</span> <span class="nu0">300</span><span class="sy0">*</span>a <span class="sy0">-</span> <span class="nu0">30</span><span class="sy0">*</span>b<span class="br0">&#41;</span>, green<span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="co1">// X coordinate.</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;gdImageLine<span class="br0">&#40;</span>im, <span class="nu0">0</span>, <span class="nu0">300</span>, <span class="nu0">600</span>, <span class="nu0">300</span>, black<span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="co1">// Y coordinate.</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;gdImageLine<span class="br0">&#40;</span>im, <span class="nu0">300</span>, <span class="nu0">0</span>, <span class="nu0">300</span>, <span class="nu0">600</span>, black<span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;fp <span class="sy0">=</span> fopen<span class="br0">&#40;</span><span class="st0">&quot;training.png&quot;</span>, <span class="st0">&quot;wb&quot;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="kw1">if</span> <span class="br0">&#40;</span>fp <span class="sy0">!=</span> <span class="nu0">0</span><span class="br0">&#41;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="br0">&#123;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;gdImagePng<span class="br0">&#40;</span>im, fp<span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;fclose<span class="br0">&#40;</span>fp<span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;<span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="br0">&#125;</span></div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; gdImageDestroy<span class="br0">&#40;</span>im<span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; system<span class="br0">&#40;</span><span class="st0">&quot;PAUSE&quot;</span><span class="br0">&#41;</span>;</div>
</li>
<li class="li1">
<div class="de1">&nbsp; &nbsp; <span class="kw1">return</span> <span class="nu0">0</span>;</div>
</li>
<li class="li1">
<div class="de1"><span class="br0">&#125;</span></div>
</li>
</ol>
</div>
<p>I used the <a href="http://www.bloodshed.net/devcpp.html">Dev C++</a> to write the program. Here is <a href="http://www.libgd.org/Devcppexample1">how to use GD in Dev C++</a>.</p>
<div id="_mcePaste" style="overflow: hidden; position: absolute; left: -10000px; top: 655px; width: 1px; height: 1px;">#include &lt;stdio.h&gt;<br />
#include &lt;stdlib.h&gt;<br />
#include &lt;gd.h&gt;<br />
#include &lt;math.h&gt;</p>
<p>float randomFloat()<br />
{<br />
srand(time(NULL));<br />
float r = (float)rand() / (float)RAND_MAX;<br />
return r;<br />
}</p>
<p>int calculateOutput(float weights[], float x, float y)<br />
{<br />
float sum = x * weights[0] + y * weights[1];<br />
return (sum &gt;= 0) ? 1 : -1;<br />
}</p>
<p>int main(int argc, char *argv[])<br />
{<br />
// X coordinates of the training set.<br />
float x[] = {<br />
-3.2, 1.1, 2.7, -1<br />
};</p>
<p>// Y coordinates of the training set.<br />
float y[] = {<br />
1.5, 3.3, 5.12, 2.1<br />
};</p>
<p>// The training set outputs.<br />
int outputs[] = {<br />
1, -1, -1, 1<br />
};</p>
<p>int patternCount = sizeof(x) / sizeof(int);</p>
<p>float weights[2];<br />
weights[0] = randomFloat();<br />
weights[1] = randomFloat();</p>
<p>float learningRate = 0.01;</p>
<p>int iteration = 0;<br />
int i, p;<br />
float globalError;</p>
<p>do {</p>
<p>globalError = 0;<br />
int p = 0; // iterator<br />
for (p = 0; p &lt; patternCount; p++)<br />
{<br />
// Calculate output.<br />
int output = calculateOutput(weights, x[p], y[p]);</p>
<p>// Calculate error.<br />
float localError = outputs[p] &#8211; output;</p>
<p>if (localError != 0)<br />
{<br />
// Update weights.<br />
for (i = 0; i &lt; 2; i++)<br />
{<br />
float add = learningRate * localError;<br />
if (i == 0)<br />
{<br />
add *= x[p];<br />
}<br />
else if (i == 1)<br />
{<br />
add *= y[p];<br />
}<br />
weights[i] +=  add;<br />
}<br />
}</p>
<p>// Convert error to absolute value.<br />
globalError += fabs(localError);</p>
<p>printf(&#8220;Iteration %d Error %5.2f\n&#8221;, iteration, globalError);</p>
<p>iteration++;<br />
}</p>
<p>} while (globalError != 0);</p>
<p>// Display network generalisation.<br />
printf(&#8220;X       Y     Output\n&#8221;);<br />
float j, k;<br />
for (j = -1; j &lt;= 1; j += .5)<br />
{<br />
for (j = -1; j &lt;= 1; j += .5)<br />
{<br />
// Calculate output.<br />
int output = calculateOutput(weights, j, k);<br />
printf(&#8220;%5.2f  %5.2f  %s\n&#8221;, j, k, (output == 1) ? &#8220;Blue&#8221; : &#8220;Red&#8221;);<br />
}<br />
}</p>
<p>// Display modified weights.<br />
printf(&#8220;Modified weights: %5.2f %5.2f\n&#8221;, weights[0], weights[1]);</p>
<p>// Create image representation.<br />
gdImagePtr im;<br />
FILE *fp;<br />
im = gdImageCreateTrueColor(600, 600);<br />
if (im != 0)<br />
{<br />
// So the points are further from each other<br />
// and the graph is more readable.<br />
int multiplier = 50;</p>
<p>// Allocate colors.<br />
int white = gdImageColorAllocate(im, 255, 255, 255);<br />
int lightGrey = gdImageColorAllocate(im, 220, 220, 220);<br />
int black = gdImageColorAllocate(im, 0, 0, 0);<br />
int blue = gdImageColorAllocate(im, 0, 0, 255);<br />
int red = gdImageColorAllocate(im, 255, 0, 0);<br />
int green = gdImageColorAllocate(im, 0, 200, 50);</p>
<p>// White flood fill.<br />
gdImageFill(im, 0, 0, lightGrey);</p>
<p>// Points.<br />
float cx, cy;<br />
for (i = 0; i &lt; patternCount; i++)<br />
{<br />
// Calculate output.<br />
int output = calculateOutput(weights, x[i], y[i]);</p>
<p>cx = floor(300 + multiplier*x[i] + 0.5);<br />
cy = floor(300 &#8211; multiplier*y[i] + 0.5);</p>
<p>int color = (output == 1) ? blue : red;</p>
<p>gdImageFilledEllipse(im, (int)cx, (int)cy, 10, 10, color);<br />
}</p>
<p>// Linear separation.<br />
float a = 0, b = 0;<br />
for (i = 0; i &lt; patternCount; i++)<br />
{<br />
int fx = (a &gt; 0 &amp;&amp; b &gt; 0) ? 1 : 0;<br />
a += learningRate * (y[i] &#8211; fx) * x[i];<br />
b += learningRate * (y[i] &#8211; fx);<br />
}<br />
printf(&#8220;y = %5.2fx + %5.2f\n&#8221;, a, b);<br />
// x = -300 =&gt; y = -300*a + b<br />
// x = 300 =&gt; y = 300*a + b<br />
gdImageLine(im, -2, (int)(300 + multiplier*300*a + b), 598, (int)(300 &#8211; multiplier*300*a + b), green);<br />
gdImageLine(im, -1, (int)(300 + multiplier*300*a + b), 599, 300 &#8211; (int)(multiplier*300*a + b), green);<br />
gdImageLine(im, 0, (int)(300 + multiplier*300*a + b), 600, 300 &#8211; (int)(multiplier*300*a + b), green);<br />
gdImageLine(im, 1, (int)(300 + multiplier*300*a + b), 601, 300 &#8211; (int)(multiplier*300*a + b), green);<br />
gdImageLine(im, 2, (int)(300 + multiplier*300*a + b), 602, 300 &#8211; (int)(multiplier*300*a + b), green);</p>
<p>// X coordinate.<br />
gdImageLine(im, 0, 300, 600, 300, black);</p>
<p>// Y coordinate.<br />
gdImageLine(im, 300, 0, 300, 600, black);</p>
<p>fp = fopen(&#8220;training.png&#8221;, &#8220;wb&#8221;);<br />
if (fp != 0)<br />
{<br />
gdImagePng(im, fp);<br />
fclose(fp);<br />
}<br />
}<br />
gdImageDestroy(im);</p>
<p>system(&#8220;PAUSE&#8221;);<br />
return 0;<br />
}</p></div>
]]></content:encoded>
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		</item>
		<item>
		<title>Clear command line, variables and command history in MATLAB</title>
		<link>http://blog.richardknop.com/2009/10/clear-command-line-variables-and-command-history-in-matlab/</link>
		<comments>http://blog.richardknop.com/2009/10/clear-command-line-variables-and-command-history-in-matlab/#comments</comments>
		<pubDate>Mon, 26 Oct 2009 14:43:54 +0000</pubDate>
		<dc:creator>Richard Knop</dc:creator>
				<category><![CDATA[MATLAB]]></category>

		<guid isPermaLink="false">http://blog.richardknop.com/?p=504</guid>
		<description><![CDATA[Here are three useful MATLAB commands.
To clear the command line:
clc
To clear all variables:
clear all
To clear the command history:
com.mathworks.mlservices.MLCommandHistoryServices.removeAll
Just putting this information down for my own reference so I won&#8217;t have to search for it later.
]]></description>
			<content:encoded><![CDATA[<p>Here are three useful MATLAB commands.</p>
<p>To clear the command line:</p>
<pre>clc</pre>
<p>To clear all variables:</p>
<pre>clear all</pre>
<p>To clear the command history:</p>
<pre>com.mathworks.mlservices.MLCommandHistoryServices.removeAll</pre>
<p>Just putting this information down for my own reference so I won&#8217;t have to search for it later.</p>
]]></content:encoded>
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</rss>
