336 lines
32 KiB
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336 lines
32 KiB
HTML
<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Creating several graphs in the same image</title><link rel="stylesheet" type="text/css" href="manual.css"><meta name="generator" content="DocBook XSL Stylesheets V1.76.0"><link rel="home" href="index.html" title="JpGraph Manual"><link rel="up" href="ch15.html" title="Chapter 15. Different types of linear (cartesian) graph types"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Creating several graphs in the same image</th></tr><tr><td width="20%" align="left"> </td><th width="60%" align="center">Chapter 15. Different types of linear (cartesian) graph types</th><td width="20%" align="right"> </td></tr></table><hr></div><div class="sect1" title="Creating several graphs in the same image"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2563880"></a>Creating several graphs in the same image</h2></div></div></div>
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<p>There are at least two reasons why one or several graphs should be combined into
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the same image.</p>
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<div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
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<p>To be able to create overall graphs that are strongly connected and
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cannot be separated</p>
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</li><li class="listitem">
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<p>To reduce the download time by only have to download one image for
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several graphs</p>
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</li><li class="listitem">
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<p>By convention, some types of graphs are always combined</p>
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</li></ul></div><p>The library provides a convenience class , <code class="code">class MGraph</code>
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(for Multi Graph) that assists with this. In order to use this class the module file
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"<code class="filename">jpgraph_mgraph.php</code>" must be included.</p>
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<p><a class="xref" href="ch15s08.html#fig.combgraphex1" title="Figure 15.88. A combination of a line graph at top and a bar graph in the bottom (combgraphex1.php)">Figure 15.88. A combination of a line graph at top and a bar graph in the bottom <code class="uri"><a class="uri" href="example_src/combgraphex1.html" target="_top">(<code class="filename">combgraphex1.php</code>)</a></code> </a> shows an example of how this can be
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used.</p>
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<p>
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</p><div class="figure"><a name="fig.combgraphex1"></a><p class="title"><b>Figure 15.88. A combination of a line graph at top and a bar graph in the bottom <code class="uri"><a class="uri" href="example_src/combgraphex1.html" target="_top">(<code class="filename">combgraphex1.php</code>)</a></code> </b></p><div class="figure-contents"> <span class="inlinemediaobject"><img src="images/combgraphex1.png" alt="A combination of a line graph at top and a bar graph in the bottom (combgraphex1.php)"></span> </div></div><p><br class="figure-break">
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</p>
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<div class="sect2" title="Creating a combined graph"><div class="titlepage"><div><div><h3 class="title"><a name="id2563975"></a>Creating a combined graph</h3></div></div></div>
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<p>In order to better understand what is involved in creating a combined graph we
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will first show how this is done manually.</p>
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<p>This is done by creating some PHP/GD code that creates a big enough empty
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image with plain GD commands and then get the image handles from the graphs that
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should be combined. The image handel can be returned from the
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<code class="code">Graph::Stroke()</code> methods in the graphs that should be included.
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It is then possible to use these handles together with the GD image copy command
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and copy the individual graph images onto the previously created empty large GD
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image.</p>
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<p>The following (almost complete) code shows how this can be done</p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-inlinetags"><?php</span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment"> Assume we would like to combine graph1,2 and 3</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment"> ...... create graph 1 here.......</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-var">$handle1</span><span class="hl-code"> = </span><span class="hl-var">$graph1</span><span class="hl-code">-></span><span class="hl-identifier">Stroke</span><span class="hl-brackets">(</span><span class="hl-code"> </span><span class="hl-identifier">_IMG_HANDLER</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-comment">//</span><span class="hl-comment"> ...... create graph 2 here.......</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-var">$handle2</span><span class="hl-code"> = </span><span class="hl-var">$graph2</span><span class="hl-code">-></span><span class="hl-identifier">Stroke</span><span class="hl-brackets">(</span><span class="hl-code"> </span><span class="hl-identifier">_IMG_HANDLER</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-comment">//</span><span class="hl-comment"> ...... create graph 3 here.......</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-var">$handle3</span><span class="hl-code"> = </span><span class="hl-var">$graph3</span><span class="hl-code">-></span><span class="hl-identifier">Stroke</span><span class="hl-brackets">(</span><span class="hl-code"> </span><span class="hl-identifier">_IMG_HANDLER</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-comment">//</span><span class="hl-comment"> Now create the "melting graph" which should contain all three graphs</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment"> $WIDTH1 and $HEIGHT1 are width and height of graph 1 ($handle1)</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment"> $WIDTH2 and $HEIGHT2 are width and height of graph 2 ($handle2)</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment"> $WIDTH3 and $HEIGHT3 are width and height of graph 3 ($handle3)</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment"> $x2,$x3 and $y2,$y3 shift from top left of global graph (ie position of </span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment"> graph2 and graph3 in global graph)</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-var">$image</span><span class="hl-code"> = </span><span class="hl-identifier">imagecreatetruecolor</span><span class="hl-brackets">(</span><span class="hl-var">$WIDTH1</span><span class="hl-code">,</span><span class="hl-var">$HEIGHT1</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-identifier">imagecopy</span><span class="hl-brackets">(</span><span class="hl-var">$image</span><span class="hl-code">, </span><span class="hl-var">$handle1</span><span class="hl-code">,</span><span class="hl-number">0</span><span class="hl-code">, </span><span class="hl-number">0</span><span class="hl-code">, </span><span class="hl-number">0</span><span class="hl-code">, </span><span class="hl-number">0</span><span class="hl-code">, </span><span class="hl-var">$WIDTH1</span><span class="hl-code">,</span><span class="hl-var">$HEIGHT1</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-identifier">imagecopy</span><span class="hl-brackets">(</span><span class="hl-var">$image</span><span class="hl-code">, </span><span class="hl-var">$handle2</span><span class="hl-code">,</span><span class="hl-var">$x1</span><span class="hl-code">,</span><span class="hl-var">$y1</span><span class="hl-code">,</span><span class="hl-number">0</span><span class="hl-code">,</span><span class="hl-number">0</span><span class="hl-code">,</span><span class="hl-var">$WIDTH2</span><span class="hl-code">,</span><span class="hl-var">$HEIGHT2</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-identifier">imagecopy</span><span class="hl-brackets">(</span><span class="hl-var">$image</span><span class="hl-code">, </span><span class="hl-var">$handle3</span><span class="hl-code">,</span><span class="hl-var">$x2</span><span class="hl-code">,</span><span class="hl-var">$y2</span><span class="hl-code">,</span><span class="hl-number">0</span><span class="hl-code">,</span><span class="hl-number">0</span><span class="hl-code">,</span><span class="hl-var">$WIDTH3</span><span class="hl-code">,</span><span class="hl-var">$HEIGHT3</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-comment">//</span><span class="hl-comment"> Stream the result back as a PNG image</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-identifier">header</span><span class="hl-brackets">(</span><span class="hl-quotes">"</span><span class="hl-string">Content-type: image/png</span><span class="hl-quotes">"</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-identifier">imagepng</span><span class="hl-code"> </span><span class="hl-brackets">(</span><span class="hl-var">$image</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-inlinetags">?></span></pre></td></tr></table></div><p>
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</p>
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<p>The advantages with this fully manual method are </p>
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<p>
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</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
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<p>Absolute full control on a pixel level how the graphs are
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combined</p>
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</li><li class="listitem">
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<p>Full transparency on how the combination is done</p>
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</li></ul></div><p>
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</p>
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<p>but on the other hand the disadvantages are</p>
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<p>
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</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
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<p>Requires knowledge of the GD library</p>
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</li><li class="listitem">
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<p>Requires re-inventing the wheel (since a lot of functionality to
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manipulate the GD library is already available in the JpGraph
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library)</p>
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</li></ul></div><p>
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</p>
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<p>It is here the <code class="code">class MGraph</code> comes in. It will allow you to very
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easily create a combination of several graphs without knowing all the details on
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the GD library or calculating pixel positions.</p>
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<p>This helper class abstracts away all the details about copying images as well
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as offering consistent interface (almost identical with the standard Graph
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class). A basic example will quickly reveal the elegance of using this helper
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class. </p>
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<p>
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-inlinetags"><?php</span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment">--------------------------------------</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment"> Graph 1</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment">--------------------------------------</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-var">$graph1</span><span class="hl-code"> = </span><span class="hl-reserved">new</span><span class="hl-code"> </span><span class="hl-identifier">Graph</span><span class="hl-brackets">(</span><span class="hl-code">...</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-comment">//</span><span class="hl-comment">... [Code to create graph1] ...</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment">--------------------------------------</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment"> Graph 2</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment">--------------------------------------</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-var">$graph2</span><span class="hl-code"> = </span><span class="hl-reserved">new</span><span class="hl-code"> </span><span class="hl-identifier">Graph</span><span class="hl-brackets">(</span><span class="hl-code">...</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-comment">//</span><span class="hl-comment">... [Code to create graph2] ...</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment">--------------------------------------</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment"> Create a combined graph</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-comment">//</span><span class="hl-comment">--------------------------------------</span><span class="hl-comment"></span><span class="hl-code">
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</span><span class="hl-var">$mgraph</span><span class="hl-code"> = </span><span class="hl-reserved">new</span><span class="hl-code"> </span><span class="hl-identifier">MGraph</span><span class="hl-brackets">(</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-var">$xpos1</span><span class="hl-code">=</span><span class="hl-number">3</span><span class="hl-code">;</span><span class="hl-var">$ypos1</span><span class="hl-code">=</span><span class="hl-number">3</span><span class="hl-code">;
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</span><span class="hl-var">$xpos2</span><span class="hl-code">=</span><span class="hl-number">3</span><span class="hl-code">;</span><span class="hl-var">$ypos2</span><span class="hl-code">=</span><span class="hl-number">200</span><span class="hl-code">;
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</span><span class="hl-var">$mgraph</span><span class="hl-code">-></span><span class="hl-identifier">Add</span><span class="hl-brackets">(</span><span class="hl-var">$graph1</span><span class="hl-code">,</span><span class="hl-var">$xpos1</span><span class="hl-code">,</span><span class="hl-var">$ypos1</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-var">$mgraph</span><span class="hl-code">-></span><span class="hl-identifier">Add</span><span class="hl-brackets">(</span><span class="hl-var">$graph2</span><span class="hl-code">,</span><span class="hl-var">$xpos2</span><span class="hl-code">,</span><span class="hl-var">$ypos2</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-var">$mgraph</span><span class="hl-code">-></span><span class="hl-identifier">Stroke</span><span class="hl-brackets">(</span><span class="hl-brackets">)</span><span class="hl-code">;
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</span><span class="hl-inlinetags">?></span></pre></td></tr></table></div><p>
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</p>
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<p>The above example illustrates the most basic usage of the <code class="code">MGraph</code>
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class. </p>
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<p>Each graph is added to the combined graph with a call to
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<code class="code">MGraph::Add()</code> which in addition to the graph argument also
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takes the target X and Y coordinates where the graph will be placed in the
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combined image. The target X and Y coordinates are relative to any optional
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specified left and top margin. </p>
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<p>In addition to adding graphs there are some basic formatting option for the
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combined graph that are listed below. The core methods provided by the
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<code class="code">MGraph</code> class are </p>
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<p>
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</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
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<p><code class="code">MGraph::MGraph($aWidth,$aHeight)</code>. </p>
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<p>Create a new instance of the <code class="code">MGraph</code> class. If the
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width and height are supplied as arguments they will override the
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automatically determined width and height. </p>
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</li><li class="listitem">
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<p><code class="code">MGraph::Add($aGraph,$aToX,$aToY,$aFromX,$aFromY,$aWidth,$aHeight).
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</code></p>
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<p>Add a new subgraph with destination position
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(<code class="code">$aToX,$aToY</code>). By default the whole graph image is
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used. It is also possible to only specify that part of the graph
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should be used. The source rectangle is specified by <code class="code">($aFromX,
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$aFromY, $aWidth, $aHeight)</code>. </p>
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</li><li class="listitem">
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<p><code class="code">MGraph::SetFillColor($aColor)</code>. </p>
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<p>Background color of the combined graphs. </p>
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<p>Example: Setting an Orange background </p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$mgraph->SetFillColor('orange');</span></pre></td></tr></table></div><p>
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</p>
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</li><li class="listitem">
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<p><code class="code">MGraph::SetFrame($aShow,$aColor,$aWeight)</code></p>
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<p>Adding a frame to the combined graph. </p>
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<p>Example: To add a blue frame with a 2 pixel width </p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$mgraph->SetFrame(true,'blue ',2);</span></pre></td></tr></table></div><p>
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</p>
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</li><li class="listitem">
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<p><code class="code">MGraph::SetMargin($aLeft,$aRight,$aTop,$aBottom)</code></p>
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<p>Adding a margin to the image. By default the minimum necessary
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size for the combined graph to hold all the added subgraphs is used.
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Use this method to add some space to the edges around the combined
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image. When the individual graphs are positioned (in the
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<code class="code">Add()</code> method) the position is counted relative to
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the left and top margin. </p>
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<p>Example: Use 10 pixel left and right margin, 5 pixel top and
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bottom margin </p>
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<p>
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</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
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</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$mgraph->SetMargin(10,10,5,5);</span></pre></td></tr></table></div><p>
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</p>
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</li><li class="listitem">
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<p><code class="code">MGraph::SetShadow($aShowShadow=true,$aShadowWidth=4,$aShadowColor='gray@0.3')</code></p>
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<p>This adds a drop shadow to the MGraph in the same way as for the
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usual graph class</p>
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</li></ul></div><p>
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</p>
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<p>In the same way as the ordinary Graph class the <code class="code">MGraph</code> class also
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have a property $footer which allows the setting of a left, center and right
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footer (see <a class="xref" href="ch14s02.html#sec.adding-footer" title="Adding a footer to the graph">Adding a footer to the graph</a>).</p>
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<p>In addition the <code class="code">MGraph::Stroke()</code> accepts a filename in the same
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way as the normal <code class="code">Graph::Stroke()</code></p>
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</div>
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<div class="sect2" title="Adding background images"><div class="titlepage"><div><div><h3 class="title"><a name="id2564308"></a>Adding background images </h3></div></div></div>
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<p>In addition to the basic usage as shown above it is also possible to add a
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background image in the combined graph. What is important to remember then is
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that all the subgraphs are copied onto the combined graph so normally they will
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be on top of the background image and hide it. </p>
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<p>There are two ways of handling a background image </p>
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<p>
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</p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
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<p>Do nothing and the background image will only "shine through" for
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those areas of the combined graph that is not covered by any
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subgraph. </p>
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</li><li class="listitem">
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<p>Specify a "blend" factor for the subgraphs that specifies how much
|
||
of the background image will be mixed with the subgraph. The blend
|
||
factor is as usual specified as an integer in the interval 0-100.
|
||
(Note: This is the same functionality as the standard
|
||
<code class="code">Graph::SetBackgroundImageMix()</code> for ordinary
|
||
graphs.) A value of 0 means that 100% of the background is visible
|
||
and a value of 100 means that 0% of the background is visible. </p>
|
||
<p>To add a subgraphs with a blend factor the method
|
||
<code class="code">MGrahp::AddMix()</code> is used. This behaves exactly as
|
||
the standard <code class="code">MGraph::Add()</code> apart from the fact that the
|
||
3:rd argument is the blend factor (after the two x and y
|
||
coordinates).</p>
|
||
<p>Example: Add a graph with 50% mix of the background </p>
|
||
<p>
|
||
</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
|
||
</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$mgraph->AddMix($graph,0,0,50);</span></pre></td></tr></table></div><p>
|
||
</p>
|
||
</li></ol></div><p>
|
||
</p>
|
||
<p>The background image itself is added with the method </p>
|
||
<p>
|
||
</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
|
||
<p><code class="code">MGraph::SetBackgroundImage($aFile,$aCenter_aX=TRUE,$aY=NULL)
|
||
</code></p>
|
||
</li></ul></div><p>
|
||
</p>
|
||
<p>The filename specifies the full name of the background image (including
|
||
extension). Please note that the extension must be a valid image extension in
|
||
order for the library to determine the format of the image file.</p>
|
||
<p>The second argument can be either numeric or a boolean in which case it
|
||
specifies if the background image should be centered or if it should just be
|
||
copied from the top left position. If it is numerical it is interpretated as the
|
||
X-position for the optional X and Y coordinates specifying the position of the
|
||
top left corner of the background image. </p>
|
||
<p><a class="xref" href="ch15s08.html#fig.combgraphex2" title="Figure 15.89. Mixing a background image with two subgraphs. In this case the mixing factor was 85 for both subgraphs. (Note: To reduce load time the image is quite hard compressed in JPEG so there are some artifacts in high-frequency areas.) (combgraphex2.php)">Figure 15.89. Mixing a background image with two subgraphs. In this case the mixing factor was 85 for both subgraphs. (Note: To reduce load time the image is quite hard compressed in JPEG so there are some artifacts in high-frequency areas.) <code class="uri"><a class="uri" href="example_src/combgraphex2.html" target="_top">(<code class="filename">combgraphex2.php</code>)</a></code> </a> shows a variant of <a class="xref" href="ch15s08.html#fig.combgraphex1" title="Figure 15.88. A combination of a line graph at top and a bar graph in the bottom (combgraphex1.php)">Figure 15.88. A combination of a line graph at top and a bar graph in the bottom <code class="uri"><a class="uri" href="example_src/combgraphex1.html" target="_top">(<code class="filename">combgraphex1.php</code>)</a></code> </a> where a centered background image is mixed
|
||
in with two subgraphs. </p>
|
||
<p>
|
||
</p><div class="figure"><a name="fig.combgraphex2"></a><p class="title"><b>Figure 15.89. Mixing a background image with two subgraphs. In this case the mixing factor was 85 for both subgraphs. (Note: To reduce load time the image is quite hard compressed in JPEG so there are some artifacts in high-frequency areas.) <code class="uri"><a class="uri" href="example_src/combgraphex2.html" target="_top">(<code class="filename">combgraphex2.php</code>)</a></code> </b></p><div class="figure-contents"> <span class="inlinemediaobject"><img src="images/combgraphex2.png" alt="Mixing a background image with two subgraphs. In this case the mixing factor was 85 for both subgraphs. (Note: To reduce load time the image is quite hard compressed in JPEG so there are some artifacts in high-frequency areas.) (combgraphex2.php)"></span> </div></div><p><br class="figure-break">
|
||
</p>
|
||
</div>
|
||
<div class="sect2" title="Creating rotated combined graphs"><div class="titlepage"><div><div><h3 class="title"><a name="id2564429"></a>Creating rotated combined graphs</h3></div></div></div>
|
||
|
||
<p>There are in principle no difference when combing graphs top/bottom or
|
||
left/right. ?? shows an example of creating a graph that illustrates the
|
||
changing weather conditions measure by Wind direction, speed and temperature in
|
||
one graph with a detailed vertical scale showing the time. </p>
|
||
<p>Since this follows exactly the same principle laid out above the script should
|
||
be fairly self explanatory. Note that we have suppressed the x-scale on two of
|
||
the graphs to make better use of the available image size and also to create a
|
||
stronger sense of "belonging" between the individual graphs.</p>
|
||
<p>
|
||
</p><div class="figure"><a name="fig.comb90dategraphex03"></a><p class="title"><b>Figure 15.90. Combining three graphs in one image <code class="uri"><a class="uri" href="example_src/comb90dategraphex03.html" target="_top">(<code class="filename">comb90dategraphex03.php</code>)</a></code> </b></p><div class="figure-contents"> <span class="inlinemediaobject"><img src="images/comb90dategraphex03.png" alt="Combining three graphs in one image (comb90dategraphex03.php)"></span> </div></div><p><br class="figure-break">
|
||
</p>
|
||
</div>
|
||
<div class="sect2" title="Some caveats when using MGraph"><div class="titlepage"><div><div><h3 class="title"><a name="id2564532"></a>Some caveats when using MGraph</h3></div></div></div>
|
||
|
||
<p>There are some drawbacks using combined graphs</p>
|
||
<p>
|
||
</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
|
||
<p>CSIM Image maps can not be used with combined graphs. </p>
|
||
</li><li class="listitem">
|
||
<p>Creating multiple graphs in the same script will require some
|
||
additional memory. Make sure that the memory limit in
|
||
"<code class="filename">php.ini</code>" is sufficient. </p>
|
||
</li><li class="listitem">
|
||
<p>Adding background images can significantly increase the final size
|
||
of the image. Using the JPEG image format when photo like background
|
||
images are used gives better compressing than PNG (since JPEG is a
|
||
lossy format). For example setting the JPEG quality parameter to 60
|
||
(default is 75). </p>
|
||
<p>
|
||
</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
|
||
</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$mgraph->SetImgFormat('jpeg',60);</span></pre></td></tr></table></div><p>
|
||
</p>
|
||
<p>
|
||
</p><div class="tip" title="Tip" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Tip</h3>
|
||
<p>This setting can be used for ordinary Graphs as well.
|
||
</p>
|
||
</div><p>
|
||
</p>
|
||
</li><li class="listitem">
|
||
<p>Compared with background images for ordinary graphs there is
|
||
currently no possibility for automatic re-sizing of the background
|
||
images. </p>
|
||
</li></ul></div><p>
|
||
</p>
|
||
</div>
|
||
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