Line and BarChart Example

The example shows how to combine different charts and set the axes.

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Publié le 27 décembre 2024 - Mis à jour le 27 décembre 2024

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Line and BarChart Example▲

In the example we combine a linechart with a barchart and use the category axis as a common axis for both.

Running the Example▲

To run the example from Qt Creator, open the Welcome mode and select the example from Examples. For more information, visit Building and Running an Example.

Combining Charts▲

Here we create data for our bar series.

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    QBarSet *set0 = new QBarSet("Jane");
    QBarSet *set1 = new QBarSet("John");
    QBarSet *set2 = new QBarSet("Axel");
    QBarSet *set3 = new QBarSet("Mary");
    QBarSet *set4 = new QBarSet("Sam");

    *set0 &lt;&lt; 1 &lt;&lt; 2 &lt;&lt; 3 &lt;&lt; 4 &lt;&lt; 5 &lt;&lt; 6;
    *set1 &lt;&lt; 5 &lt;&lt; 0 &lt;&lt; 0 &lt;&lt; 4 &lt;&lt; 0 &lt;&lt; 7;
    *set2 &lt;&lt; 3 &lt;&lt; 5 &lt;&lt; 8 &lt;&lt; 13 &lt;&lt; 8 &lt;&lt; 5;
    *set3 &lt;&lt; 5 &lt;&lt; 6 &lt;&lt; 7 &lt;&lt; 3 &lt;&lt; 4 &lt;&lt; 5;
    *set4 &lt;&lt; 9 &lt;&lt; 7 &lt;&lt; 5 &lt;&lt; 3 &lt;&lt; 1 &lt;&lt; 2;

We create a bar series and append sets to it. The first values of each set are grouped together in the first category, the second values in the second category and so on.

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    QBarSeries *barseries = new QBarSeries();
    barseries-&gt;append(set0);
    barseries-&gt;append(set1);
    barseries-&gt;append(set2);
    barseries-&gt;append(set3);
    barseries-&gt;append(set4);

Then we create a line series and add data to it. To make the data match with the barchart, we use the index as an x-value for our line series, so that first point is at (0,value) second at (1,value) and so on.

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    QLineSeries *lineseries = new QLineSeries();
    lineseries-&gt;setName("trend");
    lineseries-&gt;append(QPoint(0, 4));
    lineseries-&gt;append(QPoint(1, 15));
    lineseries-&gt;append(QPoint(2,