<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>How Do I...? — Chaco v3.4.0 documentation</title>
<link rel="stylesheet" href="../_static/default.css" type="text/css" />
<link rel="stylesheet" href="../_static/pygments.css" type="text/css" />
<script type="text/javascript">
var DOCUMENTATION_OPTIONS = {
URL_ROOT: '../',
VERSION: '3.4.0',
COLLAPSE_INDEX: false,
FILE_SUFFIX: '.html',
HAS_SOURCE: true
};
</script>
<script type="text/javascript" src="../_static/jquery.js"></script>
<script type="text/javascript" src="../_static/underscore.js"></script>
<script type="text/javascript" src="../_static/doctools.js"></script>
<link rel="shortcut icon" href="../_static/et.ico"/>
<link rel="top" title="Chaco v3.4.0 documentation" href="../index.html" />
<link rel="up" title="User Manual" href="index.html" />
<link rel="next" title="Frequently Asked Questions" href="faq.html" />
<link rel="prev" title="Common Usages" href="common_patterns.html" />
</head>
<body>
<div class="related">
<h3>Navigation</h3>
<ul>
<li class="right" style="margin-right: 10px">
<a href="faq.html" title="Frequently Asked Questions"
accesskey="N">next</a></li>
<li class="right" >
<a href="common_patterns.html" title="Common Usages"
accesskey="P">previous</a> |</li>
<li><a href="../index.html">Chaco v3.4.0 documentation</a> »</li>
<li><a href="index.html" accesskey="U">User Manual</a> »</li>
<li><a href="#">How Do I...?</a></li>
</ul>
</div>
<div class="document">
<div class="documentwrapper">
<div class="bodywrapper">
<div class="body">
<div class="section" id="how-do-i">
<h1>How Do I...?<a class="headerlink" href="#how-do-i" title="Permalink to this headline">¶</a></h1>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">This section is currently under active development.</p>
</div>
<div class="section" id="basics">
<h2>Basics<a class="headerlink" href="#basics" title="Permalink to this headline">¶</a></h2>
<p><em>How do I...</em></p>
<ul class="simple">
<li>render data to an image file?</li>
</ul>
<div class="highlight-python"><div class="highlight"><pre><span class="k">def</span> <span class="nf">save_plot</span><span class="p">(</span><span class="n">plot</span><span class="p">,</span> <span class="n">filename</span><span class="p">,</span> <span class="n">width</span><span class="p">,</span> <span class="n">height</span><span class="p">):</span>
<span class="n">plot</span><span class="o">.</span><span class="n">outer_bounds</span> <span class="o">=</span> <span class="p">[</span><span class="n">width</span><span class="p">,</span> <span class="n">height</span><span class="p">]</span>
<span class="n">plot</span><span class="o">.</span><span class="n">do_layout</span><span class="p">(</span><span class="n">force</span><span class="o">=</span><span class="bp">True</span><span class="p">)</span>
<span class="n">gc</span> <span class="o">=</span> <span class="n">PlotGraphicsContext</span><span class="p">((</span><span class="n">width</span><span class="p">,</span> <span class="n">height</span><span class="p">),</span> <span class="n">dpi</span><span class="o">=</span><span class="mi">72</span><span class="p">)</span>
<span class="n">gc</span><span class="o">.</span><span class="n">render_component</span><span class="p">(</span><span class="n">plot</span><span class="p">)</span>
<span class="n">gc</span><span class="o">.</span><span class="n">save</span><span class="p">(</span><span class="n">filename</span><span class="p">)</span>
</pre></div>
</div>
<ul class="simple">
<li>integrate a Chaco plot into my WX app?</li>
</ul>
<div class="highlight-python"><div class="highlight"><pre><span class="kn">import</span> <span class="nn">wx</span>
<span class="kn">from</span> <span class="nn">scipy</span> <span class="kn">import</span> <span class="n">arange</span>
<span class="kn">from</span> <span class="nn">scipy.special</span> <span class="kn">import</span> <span class="n">jn</span>
<span class="kn">from</span> <span class="nn">enthought.chaco.api</span> <span class="kn">import</span> <span class="n">HPlotContainer</span><span class="p">,</span> <span class="n">create_line_plot</span>
<span class="kn">from</span> <span class="nn">enthought.enable.wx_backend.api</span> <span class="kn">import</span> <span class="n">Window</span>
<span class="k">class</span> <span class="nc">PlotFrame</span><span class="p">(</span><span class="n">wx</span><span class="o">.</span><span class="n">Frame</span><span class="p">):</span>
<span class="k">def</span> <span class="nf">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="o">*</span><span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kw</span><span class="p">):</span>
<span class="n">kw</span><span class="p">[</span><span class="s">"size"</span><span class="p">]</span> <span class="o">=</span> <span class="p">(</span><span class="mi">850</span><span class="p">,</span> <span class="mi">550</span><span class="p">)</span>
<span class="n">wx</span><span class="o">.</span><span class="n">Frame</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span> <span class="o">*</span><span class="p">(</span><span class="bp">self</span><span class="p">,)</span> <span class="o">+</span> <span class="n">args</span><span class="p">,</span> <span class="o">**</span><span class="n">kw</span> <span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">plot_window</span> <span class="o">=</span> <span class="n">Window</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">component</span><span class="o">=</span><span class="bp">self</span><span class="o">.</span><span class="n">_create_plot</span><span class="p">())</span>
<span class="n">sizer</span> <span class="o">=</span> <span class="n">wx</span><span class="o">.</span><span class="n">BoxSizer</span><span class="p">(</span><span class="n">wx</span><span class="o">.</span><span class="n">HORIZONTAL</span><span class="p">)</span>
<span class="n">sizer</span><span class="o">.</span><span class="n">Add</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">plot_window</span><span class="o">.</span><span class="n">control</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="n">wx</span><span class="o">.</span><span class="n">EXPAND</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">SetSizer</span><span class="p">(</span><span class="n">sizer</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">SetAutoLayout</span><span class="p">(</span><span class="bp">True</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">Show</span><span class="p">(</span><span class="bp">True</span><span class="p">)</span>
<span class="k">return</span>
<span class="k">def</span> <span class="nf">_create_plot</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="n">x</span> <span class="o">=</span> <span class="n">arange</span><span class="p">(</span><span class="o">-</span><span class="mf">5.0</span><span class="p">,</span> <span class="mf">15.0</span><span class="p">,</span> <span class="mf">20.0</span><span class="o">/</span><span class="mi">100</span><span class="p">)</span>
<span class="n">y</span> <span class="o">=</span> <span class="n">jn</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="n">x</span><span class="p">)</span>
<span class="n">plot</span> <span class="o">=</span> <span class="n">create_line_plot</span><span class="p">((</span><span class="n">x</span><span class="p">,</span><span class="n">y</span><span class="p">),</span> <span class="n">bgcolor</span><span class="o">=</span><span class="s">"white"</span><span class="p">,</span>
<span class="n">add_grid</span><span class="o">=</span><span class="bp">True</span><span class="p">,</span> <span class="n">add_axis</span><span class="o">=</span><span class="bp">True</span><span class="p">)</span>
<span class="n">container</span> <span class="o">=</span> <span class="n">HPlotContainer</span><span class="p">(</span><span class="n">spacing</span><span class="o">=</span><span class="mi">20</span><span class="p">,</span> <span class="n">padding</span><span class="o">=</span><span class="mi">50</span><span class="p">,</span> <span class="n">bgcolor</span><span class="o">=</span><span class="s">"lightgray"</span><span class="p">)</span>
<span class="n">container</span><span class="o">.</span><span class="n">add</span><span class="p">(</span><span class="n">plot</span><span class="p">)</span>
<span class="k">return</span> <span class="n">container</span>
<span class="k">if</span> <span class="n">__name__</span> <span class="o">==</span> <span class="s">"__main__"</span><span class="p">:</span>
<span class="n">app</span> <span class="o">=</span> <span class="n">wx</span><span class="o">.</span><span class="n">PySimpleApp</span><span class="p">()</span>
<span class="n">frame</span> <span class="o">=</span> <span class="n">PlotFrame</span><span class="p">(</span><span class="bp">None</span><span class="p">)</span>
<span class="n">app</span><span class="o">.</span><span class="n">MainLoop</span><span class="p">()</span>
</pre></div>
</div>
<ul class="simple">
<li>integrate a Chaco plot into my QT app?</li>
<li>integrate a Chaco plot into my Traits UI?</li>
</ul>
<div class="highlight-python"><div class="highlight"><pre><span class="kn">import</span> <span class="nn">numpy</span>
<span class="kn">from</span> <span class="nn">enthought.chaco.api</span> <span class="kn">import</span> <span class="n">Plot</span><span class="p">,</span> <span class="n">ArrayPlotData</span>
<span class="kn">from</span> <span class="nn">enthought.enable.component_editor</span> <span class="kn">import</span> <span class="n">ComponentEditor</span>
<span class="kn">from</span> <span class="nn">enthought.traits.api</span> <span class="kn">import</span> <span class="n">HasTraits</span><span class="p">,</span> <span class="n">Instance</span>
<span class="kn">from</span> <span class="nn">enthought.traits.ui.api</span> <span class="kn">import</span> <span class="n">Item</span><span class="p">,</span> <span class="n">View</span>
<span class="k">class</span> <span class="nc">MyPlot</span><span class="p">(</span><span class="n">HasTraits</span><span class="p">):</span>
<span class="n">plot</span> <span class="o">=</span> <span class="n">Instance</span><span class="p">(</span><span class="n">Plot</span><span class="p">)</span>
<span class="n">traits_view</span> <span class="o">=</span> <span class="n">View</span><span class="p">(</span><span class="n">Item</span><span class="p">(</span><span class="s">'plot'</span><span class="p">,</span> <span class="n">editor</span><span class="o">=</span><span class="n">ComponentEditor</span><span class="p">()))</span>
<span class="k">def</span> <span class="nf">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">index</span><span class="p">,</span> <span class="n">data_series</span><span class="p">,</span> <span class="o">**</span><span class="n">kw</span><span class="p">):</span>
<span class="nb">super</span><span class="p">(</span><span class="n">MyPlot</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="o">**</span><span class="n">kw</span><span class="p">)</span>
<span class="n">plot_data</span> <span class="o">=</span> <span class="n">ArrayPlotData</span><span class="p">(</span><span class="n">index</span><span class="o">=</span><span class="n">index</span><span class="p">)</span>
<span class="n">plot_data</span><span class="o">.</span><span class="n">set_data</span><span class="p">(</span><span class="s">'data_series'</span><span class="p">,</span> <span class="n">data_series</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">plot</span> <span class="o">=</span> <span class="n">Plot</span><span class="p">(</span><span class="n">plot_data</span><span class="p">)</span>
<span class="bp">self</span><span class="o">.</span><span class="n">plot</span><span class="o">.</span><span class="n">plot</span><span class="p">((</span><span class="s">'index'</span><span class="p">,</span> <span class="s">'data_series'</span><span class="p">))</span>
<span class="n">index</span> <span class="o">=</span> <span class="n">numpy</span><span class="o">.</span><span class="n">array</span><span class="p">([</span><span class="mi">1</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">3</span><span class="p">,</span><span class="mi">4</span><span class="p">,</span><span class="mi">5</span><span class="p">])</span>
<span class="n">data_series</span> <span class="o">=</span> <span class="n">index</span><span class="o">**</span><span class="mi">2</span>
<span class="n">my_plot</span> <span class="o">=</span> <span class="n">MyPlot</span><span class="p">(</span><span class="n">index</span><span class="p">,</span> <span class="n">data_series</span><span class="p">)</span>
<span class="n">my_plot</span><span class="o">.</span><span class="n">configure_traits</span><span class="p">()</span>
</pre></div>
</div>
<ul class="simple">
<li>make an application to render many streams of data?</li>
</ul>
<div class="highlight-python"><div class="highlight"><pre><span class="k">def</span> <span class="nf">plot_several_series</span><span class="p">(</span><span class="n">index</span><span class="p">,</span> <span class="n">series_list</span><span class="p">):</span>
<span class="n">plot_data</span> <span class="o">=</span> <span class="n">ArrayPlotData</span><span class="p">(</span><span class="n">index</span><span class="o">=</span><span class="n">index</span><span class="p">)</span>
<span class="n">plot</span> <span class="o">=</span> <span class="n">Plot</span><span class="p">(</span><span class="n">plot_data</span><span class="p">)</span>
<span class="k">for</span> <span class="n">i</span><span class="p">,</span> <span class="n">data_series</span> <span class="ow">in</span> <span class="nb">enumerate</span><span class="p">(</span><span class="n">series_list</span><span class="p">):</span>
<span class="n">series_name</span> <span class="o">=</span> <span class="s">"series_</span><span class="si">%d</span><span class="s">"</span> <span class="o">%</span> <span class="n">i</span>
<span class="n">plot_data</span><span class="o">.</span><span class="n">set_data</span><span class="p">(</span><span class="n">series_name</span><span class="p">,</span> <span class="n">data_series</span><span class="p">)</span>
<span class="n">plot</span><span class="o">.</span><span class="n">plot</span><span class="p">((</span><span class="s">'index'</span><span class="p">,</span> <span class="n">series_name</span><span class="p">))</span>
</pre></div>
</div>
<ul class="simple">
<li>make a plot the right size?</li>
</ul>
<div class="highlight-python"><div class="highlight"><pre><span class="k">def</span> <span class="nf">resize_plot</span><span class="p">(</span><span class="n">plot</span><span class="p">,</span> <span class="n">width</span><span class="p">,</span> <span class="n">height</span><span class="p">):</span>
<span class="n">plot</span><span class="o">.</span><span class="n">outer_bounds</span> <span class="o">=</span> <span class="p">[</span><span class="n">width</span><span class="p">,</span> <span class="n">height</span><span class="p">]</span>
</pre></div>
</div>
<ul class="simple">
<li>copy a plot the the clipboard?</li>
</ul>
<div class="highlight-python"><div class="highlight"><pre><span class="k">def</span> <span class="nf">copy_to_clipboard</span><span class="p">(</span><span class="n">plot</span><span class="p">):</span>
<span class="c"># WX specific, though QT implementation is similar using</span>
<span class="c"># QImage and QClipboard</span>
<span class="kn">import</span> <span class="nn">wx</span>
<span class="n">width</span><span class="p">,</span> <span class="n">height</span> <span class="o">=</span> <span class="n">plot</span><span class="o">.</span><span class="n">outer_bounds</span>
<span class="n">gc</span> <span class="o">=</span> <span class="n">PlotGraphicsContext</span><span class="p">((</span><span class="n">width</span><span class="p">,</span> <span class="n">height</span><span class="p">),</span> <span class="n">dpi</span><span class="o">=</span><span class="mi">72</span><span class="p">)</span>
<span class="n">gc</span><span class="o">.</span><span class="n">render_component</span><span class="p">(</span><span class="n">plot_component</span><span class="p">)</span>
<span class="c"># Create a bitmap the same size as the plot</span>
<span class="c"># and copy the plot data to it</span>
<span class="n">bitmap</span> <span class="o">=</span> <span class="n">wx</span><span class="o">.</span><span class="n">BitmapFromBufferRGBA</span><span class="p">(</span><span class="n">width</span><span class="o">+</span><span class="mi">1</span><span class="p">,</span> <span class="n">height</span><span class="o">+</span><span class="mi">1</span><span class="p">,</span>
<span class="n">gc</span><span class="o">.</span><span class="n">bmp_array</span><span class="o">.</span><span class="n">flatten</span><span class="p">())</span>
<span class="n">data</span> <span class="o">=</span> <span class="n">wx</span><span class="o">.</span><span class="n">BitmapDataObject</span><span class="p">()</span>
<span class="n">data</span><span class="o">.</span><span class="n">SetBitmap</span><span class="p">(</span><span class="n">bitmap</span><span class="p">)</span>
<span class="k">if</span> <span class="n">wx</span><span class="o">.</span><span class="n">TheClipboard</span><span class="o">.</span><span class="n">Open</span><span class="p">():</span>
<span class="n">wx</span><span class="o">.</span><span class="n">TheClipboard</span><span class="o">.</span><span class="n">SetData</span><span class="p">(</span><span class="n">data</span><span class="p">)</span>
<span class="n">wx</span><span class="o">.</span><span class="n">TheClipboard</span><span class="o">.</span><span class="n">Close</span><span class="p">()</span>
<span class="k">else</span><span class="p">:</span>
<span class="n">wx</span><span class="o">.</span><span class="n">MessageBox</span><span class="p">(</span><span class="s">"Unable to open the clipboard."</span><span class="p">,</span> <span class="s">"Error"</span><span class="p">)</span>
</pre></div>
</div>
</div>
<div class="section" id="layout-and-rendering">
<h2>Layout and Rendering<a class="headerlink" href="#layout-and-rendering" title="Permalink to this headline">¶</a></h2>
<p><em>How do I...</em></p>
<ul class="simple">
<li>put multiple plots in a single window?</li>
<li>change the background color?</li>
</ul>
<div class="highlight-python"><div class="highlight"><pre><span class="k">def</span> <span class="nf">make_black_plot</span><span class="p">(</span><span class="n">index</span><span class="p">,</span> <span class="n">data_series</span><span class="p">):</span>
<span class="n">plot_data</span> <span class="o">=</span> <span class="n">ArrayPlotData</span><span class="p">(</span><span class="n">index</span><span class="o">=</span><span class="n">index</span><span class="p">)</span>
<span class="n">plot_data</span><span class="o">.</span><span class="n">set_data</span><span class="p">(</span><span class="s">'data_series'</span><span class="p">,</span> <span class="n">data_series</span><span class="p">)</span>
<span class="n">plot</span> <span class="o">=</span> <span class="n">Plot</span><span class="p">(</span><span class="n">plot_data</span><span class="p">,</span> <span class="n">bgcolor</span><span class="o">=</span><span class="s">'black'</span><span class="p">)</span>
<span class="n">plot</span><span class="o">.</span><span class="n">plot</span><span class="p">((</span><span class="s">'index'</span><span class="p">,</span> <span class="s">'data_series'</span><span class="p">))</span>
<span class="k">def</span> <span class="nf">change_bgcolor</span><span class="p">(</span><span class="n">plot</span><span class="p">):</span>
<span class="n">plot</span><span class="o">.</span><span class="n">bgcolor</span> <span class="o">=</span> <span class="s">'black'</span>
</pre></div>
</div>
<ul class="simple">
<li>turn off borders?</li>
</ul>
<div class="highlight-python"><div class="highlight"><pre><span class="k">def</span> <span class="nf">make_borderless_plot</span><span class="p">(</span><span class="n">index</span><span class="p">,</span> <span class="n">data_series</span><span class="p">):</span>
<span class="n">plot_data</span> <span class="o">=</span> <span class="n">ArrayPlotData</span><span class="p">(</span><span class="n">index</span><span class="o">=</span><span class="n">index</span><span class="p">)</span>
<span class="n">plot_data</span><span class="o">.</span><span class="n">set_data</span><span class="p">(</span><span class="s">'data_series'</span><span class="p">,</span> <span class="n">data_series</span><span class="p">)</span>
<span class="n">plot</span> <span class="o">=</span> <span class="n">Plot</span><span class="p">(</span><span class="n">plot_data</span><span class="p">,</span> <span class="n">border_visible</span><span class="o">=</span><span class="bp">False</span><span class="p">)</span>
<span class="n">plot</span><span class="o">.</span><span class="n">plot</span><span class="p">((</span><span class="s">'index'</span><span class="p">,</span> <span class="s">'data_series'</span><span class="p">))</span>
<span class="k">def</span> <span class="nf">change_to_borderless_plot</span><span class="p">(</span><span class="n">plot</span><span class="p">):</span>
<span class="n">plot</span><span class="o">.</span><span class="n">border_visible</span> <span class="o">=</span> <span class="bp">False</span>
</pre></div>
</div>
</div>
<div class="section" id="writing-components">
<h2>Writing Components<a class="headerlink" href="#writing-components" title="Permalink to this headline">¶</a></h2>
<p><em>How do I...</em></p>
<ul class="simple">
<li>compose multiple renderers?</li>
<li>write a custom renderer?</li>
<li>write a custom overlay/underlay?</li>
<li>write a custom tool?</li>
<li>write a new container?</li>
</ul>
</div>
<div class="section" id="advanced">
<h2>Advanced<a class="headerlink" href="#advanced" title="Permalink to this headline">¶</a></h2>
<p><em>How do I...</em></p>
<ul class="simple">
<li>properly change/override draw dispatch?</li>
<li>modify event dispatch?</li>
<li>customize backbuffering?</li>
<li>embed custom/native WX widgets on the plot?</li>
</ul>
</div>
</div>
</div>
</div>
</div>
<div class="sphinxsidebar">
<div class="sphinxsidebarwrapper">
<p class="logo"><a href="../index.html">
<img class="logo" src="../_static/e-logo-rev.png" alt="Logo"/>
</a></p>
<h3>Page Contents</h3>
<ul>
<li><a class="reference internal" href="#">How Do I...?</a><ul>
<li><a class="reference internal" href="#basics">Basics</a></li>
<li><a class="reference internal" href="#layout-and-rendering">Layout and Rendering</a></li>
<li><a class="reference internal" href="#writing-components">Writing Components</a></li>
<li><a class="reference internal" href="#advanced">Advanced</a></li>
</ul>
</li>
</ul>
<h3>This Page</h3>
<ul class="this-page-menu">
<li><a href="../_sources/user_manual/how_do_i.txt"
rel="nofollow">Show Source</a></li>
</ul>
<div id="searchbox" style="display: none">
<h3>Quick search</h3>
<form class="search" action="../search.html" method="get">
<input type="text" name="q" size="18" />
<input type="submit" value="Go" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
<p class="searchtip" style="font-size: 90%">
Enter search terms or a module, class or function name.
</p>
</div>
<script type="text/javascript">$('#searchbox').show(0);</script>
</div>
</div>
<div class="clearer"></div>
</div>
<div class="related">
<h3>Navigation</h3>
<ul>
<li class="right" style="margin-right: 10px">
<a href="faq.html" title="Frequently Asked Questions"
>next</a></li>
<li class="right" >
<a href="common_patterns.html" title="Common Usages"
>previous</a> |</li>
<li><a href="../index.html">Chaco v3.4.0 documentation</a> »</li>
<li><a href="index.html" >User Manual</a> »</li>
<li><a href="#">How Do I...?</a></li>
</ul>
</div>
<div class="footer">
© Copyright 2008, Enthought, Inc..
Last updated on Mar 02, 2011.
Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.0.7.
</div>
</body>
</html>
