<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Chapter 21. Windrose</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="pt05.html" title="Part V. Additional graph types available in the professional version"></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">Chapter 21. Windrose</th></tr><tr><td width="20%" align="left"> </td><th width="60%" align="center">Part V. Additional graph types available in the professional version</th><td width="20%" align="right"> </td></tr></table><hr></div><div class="chapter" title="Chapter 21. Windrose"><div class="titlepage"><div><div><h2 class="title"><a name="id2586258"></a>Chapter 21. Windrose</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="ch21.html#id2586284">21.1. Introduction</a></span></dt><dd><dl><dt><span class="sect2"><a href="ch21.html#id2586553">21.1.1. Features</a></span></dt><dt><span class="sect2"><a href="ch21.html#id2586667">21.1.2. Different types of Windrose plots</a></span></dt></dl></dd><dt><span class="sect1"><a href="ch21s02.html">21.2. Creating and formatting basic Windrose graphs</a></span></dt><dd><dl><dt><span class="sect2"><a href="ch21s02.html#id2587433">21.2.1. Specifying the windrose scale</a></span></dt><dt><span class="sect2"><a href="ch21s02.html#id2587804">21.2.2. Specifying direction labels</a></span></dt></dl></dd><dt><span class="sect1"><a href="ch21s03.html">21.3. Formatting the plot</a></span></dt><dd><dl><dt><span class="sect2"><a href="ch21s03.html#id2588150">21.3.1. Positioning the plot</a></span></dt><dt><span class="sect2"><a href="ch21s03.html#id2588191">21.3.2. Specifying the size of the plot</a></span></dt><dt><span class="sect2"><a href="ch21s03.html#id2588242">21.3.3. Specifying the size of the Zero-circle (middle circle)</a></span></dt><dt><span class="sect2"><a href="ch21s03.html#id2588292">21.3.4. Formatting the plot legend</a></span></dt><dt><span class="sect2"><a href="ch21s03.html#id2588295">21.3.5. Adjusting the grid colors</a></span></dt><dt><span class="sect2"><a href="ch21s03.html#id2588776">21.3.6. Adjusting the weight of the grid circles</a></span></dt><dt><span class="sect2"><a href="ch21s03.html#id2588868">21.3.7. Adding a box around the plot</a></span></dt><dt><span class="sect2"><a href="ch21s03.html#id2588901">21.3.8. Adjusting the size of the center zero circle</a></span></dt><dt><span class="sect2"><a href="ch21s03.html#sec.windrose-locale-compass">21.3.9. Localizing the default names for the compass directions</a></span></dt><dt><span class="sect2"><a href="ch21s03.html#id2589068">21.3.10. Adjusting the formatting of the windrose plot legs</a></span></dt></dl></dd><dt><span class="sect1"><a href="ch21s04.html">21.4. Some more advanced formatting</a></span></dt><dd><dl><dt><span class="sect2"><a href="ch21s04.html#id2589161">21.4.1. Turning off Anti-aliasing</a></span></dt><dt><span class="sect2"><a href="ch21s04.html#id2589188">21.4.2. More on formatting scale-labels</a></span></dt><dt><span class="sect2"><a href="ch21s04.html#id2589422">21.4.3. Formatting the legend </a></span></dt><dt><span class="sect2"><a href="ch21s04.html#id2589687">21.4.4. Highlighting specific compass directions</a></span></dt><dt><span class="sect2"><a href="ch21s04.html#id2589778">21.4.5. Including a graph in a PDF</a></span></dt><dt><span class="sect2"><a href="ch21s04.html#id2589844">21.4.6. Adding a background image</a></span></dt><dt><span class="sect2"><a href="ch21s04.html#id2589846">21.4.7. Adjusting the interpretation for ordinal keys in data</a></span></dt></dl></dd><dt><span class="sect1"><a href="ch21s05.html">21.5. Adding icon and text objects to the graph</a></span></dt><dd><dl><dt><span class="sect2"><a href="ch21s05.html#id2590083">21.5.1. Adding a text object</a></span></dt><dt><span class="sect2"><a href="ch21s05.html#id2590085">21.5.2. Adding icons to the graph</a></span></dt></dl></dd><dt><span class="sect1"><a href="ch21s06.html">21.6. Using layout classes to position Windrose plots</a></span></dt><dt><span class="sect1"><a href="ch21s07.html">21.7. Example section</a></span></dt><dd><dl><dt><span class="sect2"><a href="ch21s07.html#id2590489">21.7.1. Example 1</a></span></dt><dt><span class="sect2"><a href="ch21s07.html#id2590558">21.7.2. Example 2</a></span></dt><dt><span class="sect2"><a href="ch21s07.html#id2590662">21.7.3. Example 3</a></span></dt><dt><span class="sect2"><a href="ch21s07.html#id2590781">21.7.4. Example 4</a></span></dt><dt><span class="sect2"><a href="ch21s07.html#id2590808">21.7.5. Example 5</a></span></dt><dt><span class="sect2"><a href="ch21s07.html#id2591019">21.7.6. Example 6</a></span></dt><dt><span class="sect2"><a href="ch21s07.html#id2591106">21.7.7. Example 7</a></span></dt><dt><span class="sect2"><a href="ch21s07.html#id2591253">21.7.8. Example 8</a></span></dt><dt><span class="sect2"><a href="ch21s07.html#id2591304">21.7.9. Example 9</a></span></dt><dt><span class="sect2"><a href="ch21s07.html#sec.windrose-ex10">21.7.10. Example 10</a></span></dt></dl></dd></dl></div>
<div class="sect1" title="Introduction"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2586284"></a>Introduction</h2></div></div></div>
<div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>This module is only available in the pro-version of the library.</p></div>
<p>Windrose plots are usually used to display values which are related to compass
directions. For example it could be used to illustrate measured wind strengths over a
time period in different directions. <a class="xref" href="ch21.html#fig.windrose-intro" title="Figure 21.1. An basic Windrose plot">Figure 21.1. An basic Windrose plot</a>
Illustrates a basic example of a windrose graph with one windrose plot.</p>
<div class="figure"><a name="fig.windrose-intro"></a><p class="title"><b>Figure 21.1. An basic Windrose plot</b></p><div class="figure-contents">
<div class="mediaobject"><img src="images/windrose_intro.png" alt="An basic Windrose plot"></div>
</div></div><br class="figure-break">
<p>Windrose plots puts data in a number of ranges (or buckets). The number of data points
in a certain bucket is visualized by the length of the particular bucket in that
direction. The input data specifies the percentage of the overall data that belongs to
one bucket in one specific direction. By default there are eight buckets with ranges
shown in <a class="xref" href="ch21.html#table.windrose-default-buckets" title="Table 21.1. Default windrose buckets">Table 21.1. Default windrose buckets</a>. The default ranges that
is shown in the legend is standard values used in displaying wind strengths. The values
in the legend (for the buckets) is purely informational since the actual display is
controlled by the input data that only specifies a bucket number and not any absolute
data values. See more on how to specify input data in ??</p>
<p>
</p><div class="table"><a name="table.windrose-default-buckets"></a><p class="title"><b>Table 21.1. Default windrose buckets</b></p><div class="table-contents">
<table summary="Default windrose buckets" border="1"><colgroup><col class="c1"><col class="c2"></colgroup><thead><tr><th>Bucket nr </th><th>Range of values </th></tr></thead><tbody><tr><td align="center">0</td><td>[0,1]</td></tr><tr><td align="center">1</td><td>[1,2]</td></tr><tr><td align="center">2</td><td>[2,3]</td></tr><tr><td align="center">3</td><td>[3,5]</td></tr><tr><td align="center">4</td><td>[5,6]</td></tr><tr><td align="center">5</td><td>[6,10]</td></tr><tr><td align="center">6</td><td>[10,13.5]</td></tr><tr><td align="center">7</td><td>[13.5,99]</td></tr></tbody></table>
</div></div><p><br class="table-break">
</p>
<p>
</p><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3>
<p>The default fonts for Windrose graphs are TTF fonts. This means that to run
the examples exactly as shown in this chapter TTF fonts must be installed. If
TTF fonts are not available then the font needs to be changed to one of the
built-in fonts. </p>
</div><p>
</p>
<p>Windrose plots also supports full image anti-aliasing to enhance the look and feel of
the graph. The image in <a class="xref" href="ch21.html#fig.windrose-intro" title="Figure 21.1. An basic Windrose plot">Figure 21.1. An basic Windrose plot</a> is using
anti-alias.</p>
<p>
</p><div class="caution" title="Caution" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Caution</h3>
<p>To use anti alias TTF fonts must be enabled and used.</p>
</div><p>
</p>
<div class="sect2" title="Features"><div class="titlepage"><div><div><h3 class="title"><a name="id2586553"></a>Features</h3></div></div></div>
<p>The Windrose extension module supports all the usual library graph capabilities
like frames, shadows, colors, titles, cache. Some of the additional Windrose graphs
capabilities are: </p>
<p>
</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
<p>Enhanced anti-alias capability for smooth looking graphs</p>
</li><li class="listitem">
<p>Manual or automatic scale</p>
</li><li class="listitem">
<p>Supports customizable compass types which allow you to choose between
16,8 and 4 compass directions to be shown.</p>
</li><li class="listitem">
<p>Supports two types of basic graphs; Free direction graphs and compass
bound graphs.</p>
</li><li class="listitem">
<p>Allows data to be specified with both compass direction and angles (in
degrees)</p>
</li><li class="listitem">
<p>Fully customizable fonts everywhere in the plot</p>
</li><li class="listitem">
<p>Fully automatic adaptive positioning of the labels for the scale to
avoid collision with data. This can also be turned off to allow manual
positioning of the labels.</p>
</li><li class="listitem">
<p>Labels have extensive formatting capabilities and supports background
colors, rounded boxes and arbitrary fonts.</p>
</li><li class="listitem">
<p>Supports multiple Windrose graphs on the same image</p>
</li><li class="listitem">
<p>Fully customizable size and positioning of each individual windrose
graph.</p>
</li><li class="listitem">
<p>Size of windrose plots can be specified both as absolute pixels or as
fraction of the graph size.</p>
</li><li class="listitem">
<p>Both manual and automatic color specifications</p>
</li><li class="listitem">
<p>Both automatic and manual scaling</p>
</li><li class="listitem">
<p>Intelligent positioning of angle labels with possibility for client
specification of alignment type.</p>
</li><li class="listitem">
<p>Windrose graphs may have arbitrary texts blocks added to the
graph</p>
</li></ul></div><p>
</p>
</div>
<div class="sect2" title="Different types of Windrose plots"><div class="titlepage"><div><div><h3 class="title"><a name="id2586667"></a>Different types of Windrose plots</h3></div></div></div>
<p>There are two basic types of Windrose plots: </p>
<p>
</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
<p><span class="bold"><strong>Compass type. </strong></span></p>
<p>This type of windrose plot has either 4,8 or 16 compass direction
axis. Directions in input data is limited to one of the compass
directions in the plot. The directions are specified as ordinal number
of the direction axis. </p>
<p>The labels on the axis is by default short forms of the compass
directions, for example, "E", "N", "W", "S". (See ?? for how to alter
the default names of the compass directions). The ordinal number are
counted anti-clockwise from East (3 o'clock).</p>
</li><li class="listitem">
<p><span class="bold"><strong>Free type. </strong></span></p>
<p>This type of windrose plot has no pre-defined direction axis.
Directions in input data can be arbitrary angles (or specified as
compass directions e.g. "NW"). The 0-angle corresponds to the East
direction (3 o'clock)</p>
</li></ul></div><p>
</p>
<p>To specify the type of plot to create the following method is used</p>
<p>
</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
<p><code class="code">WindrosePlot::SetType($aDirection)</code>
</p>
<p><code class="code">$aDirection</code> is one of the following 4 predefined
constants</p>
<p>
</p><div class="itemizedlist"><ul class="itemizedlist" type="circle"><li class="listitem">
<p><code class="code">WINDROSE_TYPE4</code>, Compass type with the four
core compass directions</p>
</li><li class="listitem">
<p><code class="code">WINDROSE_TYPE8</code>, Compass type with eight
directions</p>
</li><li class="listitem">
<p><code class="code">WINDROSE_TYPE16</code>, Compass type with sixteen
directions</p>
</li><li class="listitem">
<p><code class="code">WINDROSE_TYPEFREE</code>, Free type. Data directions
can be arbitrary angles and there are no predefined labels
nor any predefined axis.</p>
</li></ul></div><p>
</p>
</li></ul></div><p>
</p>
<p>The figures below illustrates the basic principle of the different types of
windrose plots</p>
<p>
<table xmlns="" frame="void" id="id2586849">
<tbody xmlns="">
<tr>
<td align="center">
<div class="figure"><a name="id2586867"></a><p class="title"><b>Figure 21.2. <code class="code">WINDROSE_TYPE4</code></b></p><div class="figure-contents">
<div class="mediaobject"><img src="images/windrose_type4.png" alt="WINDROSE_TYPE4"></div>
</div></div><br class="figure-break">
</td>
<td align="center">
<div class="figure"><a name="id2586898"></a><p class="title"><b>Figure 21.3. <code class="code">WINDROSE_TYPE8</code></b></p><div class="figure-contents">
<div class="mediaobject"><img src="images/windrose_type8.png" alt="WINDROSE_TYPE8"></div>
</div></div><br class="figure-break">
</td>
</tr>
<tr>
<td align="center">
<div class="figure"><a name="id2586927"></a><p class="title"><b>Figure 21.4. <code class="code">WINDROSE_TYPE16</code></b></p><div class="figure-contents">
<div class="mediaobject"><img src="images/windrose_type16.png" alt="WINDROSE_TYPE16"></div>
</div></div><br class="figure-break">
</td>
<td align="center">
<div class="figure"><a name="id2586957"></a><p class="title"><b>Figure 21.5. <code class="code">WINDROSE_TYPEFREE</code></b></p><div class="figure-contents">
<div class="mediaobject"><img src="images/windrose_typefree.png" alt="WINDROSE_TYPEFREE"></div>
</div></div><br class="figure-break">
</td>
</tr>
</tbody>
</table>
</p>
<p>The following line would specify a Windrose plot with all 16 compass angles </p>
<p>
</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
2
3
4
</pre></td><td class="hl-main" valign="top"><pre><span class="hl-inlinetags"><?php</span><span class="hl-code">
</span><span class="hl-var">$wp</span><span class="hl-code"> = </span><span class="hl-reserved">new</span><span class="hl-code"> </span><span class="hl-identifier">WindrosePlot</span><span class="hl-brackets">(</span><span class="hl-var">$data</span><span class="hl-brackets">)</span><span class="hl-code">;
</span><span class="hl-var">$wp</span><span class="hl-code">-></span><span class="hl-identifier">SetType</span><span class="hl-brackets">(</span><span class="hl-identifier">WINDROSE_TYPE16</span><span class="hl-brackets">)</span><span class="hl-code">;
</span><span class="hl-inlinetags">?></span></pre></td></tr></table></div><p>
</p>
<p>
</p><div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3>
<p>If no type is specified the plot type will default to a compass type with
16 directions</p>
</div><p>
</p>
<div class="sect3" title="Specifying input data"><div class="titlepage"><div><div><h4 class="title"><a name="id2587005"></a>Specifying input data</h4></div></div></div>
<p>Input data is in the form of a data array. Each entry in the array is itself
an array which gives the data for one direction. The data should be interpreted
as the percentage of the overall data that belongs to a certain direction and
bucket. This also means that the total sum of all data entries (for all
doirections) must be less or equal to 100. It can however be less than 100
(indicating that some data is lost). </p>
<p>The first bucket, bucket 0, specifies the 0-value, i.e. what part of the data
in that direction that has no measurement (e.g. it was wind still). Since wind
still has no direction all specified bucket 0 are summarized and displayed in
the inner circle.</p>
<p>By default the ranges displayed on the legend are:</p>
<p>0-1, 1-2, 2-3, 3-5, 5-6, 6-10, 10-13.5, 13-99</p>
<p>This means that the first element specify the percentage of 0-1 reading the
sum of these reading will be placed in the center of the windrose plot. The
second element specifies the percentage of 1-2 readings, the third element the
percentage of 2-3 readings and so on.</p>
<p>The direction is specified as the key for that element. The direction can be
specified as either </p>
<p>
</p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem">
<p>A string specifying any of the displayed compass directions, e.g.
"N", "SW".</p>
<p>
</p><pre class="screen">$data = array ( array('E' => <east_bucket0>,<east_bucket1> ... <east_bucketN> ),
array('ESE' => <eastsoutheast_bucket0>, ... <eastsoutheast_bucketN> ),
....
array('NE' => <northeast_bucket0>, ... <northeast_bucketN> ),
array('ENE' => <eastnortheast_bucket0>, ... <eastnortheast_bucketN> ));</pre><p>
</p>
</li><li class="listitem">
<p>An ordinal number (integer) in the range 0-15 for regular plots
which indicates the axis counting anti-clockwise from East. Please
note that only displayed axis count. Ordinal number zero specifies
the east direction</p>
<p>
</p><pre class="screen">$data = array ( array(0 => <east_bucket0>,<east_bucket1> ... <east_bucketN> ),
array(1 => <eastsoutheast_bucket0>, ... <eastsoutheast_bucketN> ),
....
array(2 => <northeast_bucket0>, ... <northeast_bucketN> ),
array(3 => <eastnortheast_bucket0>, ... <eastnortheast_bucketN> ));</pre><p>
</p>
</li><li class="listitem">
<p>A string indicating a number, e.g. '34.5' , please note that if
the angle is a fraction it must specified as a string. The library
will then automatically recognize that as a valid angle and treat it
as expected. (The reason for this is that floating point numbers
can't be used as keys in an associative array.)</p>
<p>
</p><pre class="screen">$data = array ( array('12.5' => <bucket0>,<bucket1> ... <bucketN> ),
array('22.1' => <bucket0>, ... <bucketN> ),
....
</pre><p>
</p>
</li></ul></div><p>
</p>
<p>Within the same data set it is also possible to mix the styles.</p>
<p>
</p><div class="caution" title="Caution" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Caution</h3>
<p>The library makes no data validation apart from checking that the
overall sum of the buckets can not be > 100%. It is up to the client to
make sure that the data specified makes sense.</p>
</div><p>
</p>
<p>If you specify a direction in the data for a compass directions that is not
displayed when using a regular Windrose plot you will get an error message to
that affect. </p>
<p>Below are some examples of how to specify the data which should clarify how
this works</p>
<p>
</p><div class="example"><a name="id2587141"></a><p class="title"><b>Example 21.1. Examples of input data for compass (regular) Windrose plots</b></p><div class="example-contents">
<p><span class="italic">(Assuming we have all 16 axis
displayed)</span></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">$data = array( 'N' => array(2,5,6) );</span></pre></td></tr></table></div><p>
</p>
<p>This data array specifies reading in only one direction, "North", the
number of 0-readings are 2 percent, number of 0-1 readings are 5 percent
and the number of 1-2 readings are 6 percent. </p>
<p>
</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$data = array( 1 => array(2,5,6), 3 => array(6,3), 'NW' => array(3,2,2,2) )</span></pre></td></tr></table></div><p>
</p>
<p>This data array specifies readings in three directions. As shown it is
possible to mix both ordinal number for the axis as well as the symbolic
direction name. However, it is probably best to stick with one method at
a time for clarity.</p>
</div></div><p><br class="example-break">
</p>
<p>
</p><div class="example"><a name="id2587190"></a><p class="title"><b>Example 21.2. Examples of input data for free Windrose plots</b></p><div class="example-contents">
<p>What is special with the free type is that angles are no longer
restricted to only the 16 compass directions but arbitrary directions as
well. </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">$data = array( 10 => array(2,5,6), 24 => array(6,3), 137 => array(3,2,2,2) )</span></pre></td></tr></table></div><p>
</p>
<p>This data array specifies readings in three directions, 10 degrees, 24
degrees and 137 degrees. </p>
<p>
</p><div class="hl-main"><table class="hl-table" width="100%"><tr><td class="hl-gutter" align="right" valign="top"><pre>1
</pre></td><td class="hl-main" valign="top"><pre><span class="hl-code">$data = array( '21.6' => array(2,5,6), 'N' => array(6,3), 137 => array(3,2,2,2) )</span></pre></td></tr></table></div><p>
</p>
<p>This data array specifies readings in three directions, 21.5 degrees,
'North' (or 90 degrees) and finally 137 degrees. Please note that in
order to specify a fraction for an angle we must specify the direction
as a string value, i.e. '21.6'. This will then be handled automatically
be the library. </p>
</div></div><p><br class="example-break">
</p>
</div>
</div>
</div>
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