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qtcharts5-doc-5.9.4-1.mga6.noarch.rpm

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<td >Qt 5.9</td><td ><a href="qtcharts-index.html">Qt Charts</a></td><td ><a href="qtcharts-examples.html">Qt Charts Examples</a></td><td >PercentBarChart Example</td></tr></table><table class="buildversion"><tr>
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<h3><a name="toc">Contents</a></h3>
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<li class="level1"><a href="#running-the-example">Running the Example</a></li>
<li class="level1"><a href="#creating-percent-bar-charts">Creating Percent Bar Charts</a></li>
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<h1 class="title">PercentBarChart Example</h1>
<span class="subtitle"></span>
<!-- $$$percentbarchart-description -->
<div class="descr"> <a name="details"></a>
<p>A percent bar chart shows the data in sets as a percentage of all sets per category.</p>
<p>Creating percent bar charts is just like creating a regular <a href="qtcharts-barchart-example.html">bar chart</a>, except that for a percent bar charts, we use the <a href="qpercentbarseries.html">QPercentBarSeries</a> api instead of <a href="qbarseries.html">QBarSeries</a>. Also, in the <a href="qtcharts-barchart-example.html">bar chart</a> we used the nice numbers algorithm to make the y-axis numbering look better. With the percent bar chart there is no need for that, because the maximum y-axis value is always 100.</p>
<p class="centerAlign"><img src="images/examples_percentbarchart.png" alt="" /></p><a name="running-the-example"></a>
<h2 id="running-the-example">Running the Example</h2>
<p>To run the example from Qt Creator, open the <b>Welcome</b> mode and select the example from <b>Examples</b>. For more information, visit Building and Running an Example.</p>
<a name="creating-percent-bar-charts"></a>
<h2 id="creating-percent-bar-charts">Creating Percent Bar Charts</h2>
<p>The barsets are used in same way in all barcharts. To illustrate the difference between various barcharts, we use the same data in all examples. The data visualized by the bar chart is defined by <a href="qbarset.html">QBarSet</a> instances. Here we create the sets and append data to them. The data is appended here with the &lt;&lt; operator. Alternatively the append method could be used.</p>
<pre class="cpp">

      <span class="type"><a href="qbarset.html">QBarSet</a></span> <span class="operator">*</span>set0 <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qbarset.html">QBarSet</a></span>(<span class="string">&quot;Jane&quot;</span>);
      <span class="type"><a href="qbarset.html">QBarSet</a></span> <span class="operator">*</span>set1 <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qbarset.html">QBarSet</a></span>(<span class="string">&quot;John&quot;</span>);
      <span class="type"><a href="qbarset.html">QBarSet</a></span> <span class="operator">*</span>set2 <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qbarset.html">QBarSet</a></span>(<span class="string">&quot;Axel&quot;</span>);
      <span class="type"><a href="qbarset.html">QBarSet</a></span> <span class="operator">*</span>set3 <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qbarset.html">QBarSet</a></span>(<span class="string">&quot;Mary&quot;</span>);
      <span class="type"><a href="qbarset.html">QBarSet</a></span> <span class="operator">*</span>set4 <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qbarset.html">QBarSet</a></span>(<span class="string">&quot;Samantha&quot;</span>);

      <span class="operator">*</span>set0 <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">1</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">2</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">3</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">4</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">5</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">6</span>;
      <span class="operator">*</span>set1 <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">5</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">0</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">0</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">4</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">0</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">7</span>;
      <span class="operator">*</span>set2 <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">3</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">5</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">8</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">13</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">8</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">5</span>;
      <span class="operator">*</span>set3 <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">5</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">6</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">7</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">3</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">4</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">5</span>;
      <span class="operator">*</span>set4 <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">9</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">7</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">5</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">3</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">1</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="number">2</span>;

</pre>
<p>We create the series and append the barsets to it. The series takes ownership of the barsets. The series groups the data from sets to categories. The first values of each set are grouped together in the first category, the second values in the second category etc.</p>
<pre class="cpp">

      <span class="type"><a href="qpercentbarseries.html">QPercentBarSeries</a></span> <span class="operator">*</span>series <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qpercentbarseries.html">QPercentBarSeries</a></span>();
      series<span class="operator">-</span><span class="operator">&gt;</span>append(set0);
      series<span class="operator">-</span><span class="operator">&gt;</span>append(set1);
      series<span class="operator">-</span><span class="operator">&gt;</span>append(set2);
      series<span class="operator">-</span><span class="operator">&gt;</span>append(set3);
      series<span class="operator">-</span><span class="operator">&gt;</span>append(set4);

</pre>
<p>Here we create the chart object and add the series to it. We set the title of the chart with setTitle, and then turn on animations of the series by calling setAnimationOptions(<a href="qchart.html#AnimationOption-enum">QChart::SeriesAnimations</a>)</p>
<pre class="cpp">

      <span class="type"><a href="qchart.html">QChart</a></span> <span class="operator">*</span>chart <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qchart.html">QChart</a></span>();
      chart<span class="operator">-</span><span class="operator">&gt;</span>addSeries(series);
      chart<span class="operator">-</span><span class="operator">&gt;</span>setTitle(<span class="string">&quot;Simple percentbarchart example&quot;</span>);
      chart<span class="operator">-</span><span class="operator">&gt;</span>setAnimationOptions(<span class="type"><a href="qchart.html">QChart</a></span><span class="operator">::</span>SeriesAnimations);

</pre>
<p>To have categories displayed on axis, we need to create a <a href="qbarcategoryaxis.html">QBarCategoryAxis</a> for that. Here we create a category axis with a list of categories and set it to be the x-axis of the chart. The chart takes ownership of the axis. For the y-axis we use the default axis, which is created and scaled to series data by calling createDefaultAxes of the chart. Note that createDefaultAxes must be called before we set the category axis. Otherwise the default axis will override the category axis.</p>
<pre class="cpp">

      <span class="type">QStringList</span> categories;
      categories <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="string">&quot;Jan&quot;</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="string">&quot;Feb&quot;</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="string">&quot;Mar&quot;</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="string">&quot;Apr&quot;</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="string">&quot;May&quot;</span> <span class="operator">&lt;</span><span class="operator">&lt;</span> <span class="string">&quot;Jun&quot;</span>;
      <span class="type"><a href="qbarcategoryaxis.html">QBarCategoryAxis</a></span> <span class="operator">*</span>axis <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qbarcategoryaxis.html">QBarCategoryAxis</a></span>();
      axis<span class="operator">-</span><span class="operator">&gt;</span>append(categories);
      chart<span class="operator">-</span><span class="operator">&gt;</span>createDefaultAxes();
      chart<span class="operator">-</span><span class="operator">&gt;</span>setAxisX(axis<span class="operator">,</span> series);

</pre>
<p>We also want to show the legend. To do so, we get the legend pointer from the chart and set it to visible. We also place the legend to bottom of the chart by setting its alignment to Qt::AlignBottom.</p>
<pre class="cpp">

      chart<span class="operator">-</span><span class="operator">&gt;</span>legend()<span class="operator">-</span><span class="operator">&gt;</span>setVisible(<span class="keyword">true</span>);
      chart<span class="operator">-</span><span class="operator">&gt;</span>legend()<span class="operator">-</span><span class="operator">&gt;</span>setAlignment(<span class="type">Qt</span><span class="operator">::</span>AlignBottom);

</pre>
<p>Finally we add the chart onto a view. We also turn on the antialiasing for the chartView.</p>
<pre class="cpp">

      <span class="type"><a href="qchartview.html">QChartView</a></span> <span class="operator">*</span>chartView <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qchartview.html">QChartView</a></span>(chart);
      chartView<span class="operator">-</span><span class="operator">&gt;</span>setRenderHint(<span class="type">QPainter</span><span class="operator">::</span>Antialiasing);

</pre>
<p>The chart is ready to be shown. We set the chart to be central widget of the window. We also set the size for the chart window and show it.</p>
<pre class="cpp">

      <span class="type">QMainWindow</span> window;
      window<span class="operator">.</span>setCentralWidget(chartView);
      window<span class="operator">.</span>resize(<span class="number">420</span><span class="operator">,</span> <span class="number">300</span>);
      window<span class="operator">.</span>show();

</pre>
<p>Files:</p>
<ul>
<li><a href="qtcharts-percentbarchart-main-cpp.html">percentbarchart/main.cpp</a></li>
<li><a href="qtcharts-percentbarchart-percentbarchart-pro.html">percentbarchart/percentbarchart.pro</a></li>
</ul>
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