Qt - How do I define the spacing of the axes on a QCustomPlot?
I am using QCustomPlot
, on Qt, to display aspects of a video sequence.
I would like to define the background of my graph in order to define specific zones along mine yAxis
. My schedule is like this:
And I would like to define the intervals in mine yAxis
to get something like this:
The last image is from a program called PEAT, which is used to analyze videos that can cause epileptic seizures. I point out that they define zones along yAxis
.
Any suggestions?
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To have an area on the chart, you can add two plots that define the boundaries of the area:
//Upper bound
customPlot->addGraph();
QPen pen;
pen.setStyle(Qt::DotLine);
pen.setWidth(1);
pen.setColor(QColor(180,180,180));
customPlot->graph(0)->setName("Pass Band");
customPlot->graph(0)->setPen(pen);
customPlot->graph(0)->setBrush(QBrush(QColor(255,50,30,20)));
//Lower bound
customPlot->addGraph();
customPlot->legend->removeItem(customPlot->legend->itemCount()-1); // don't show two Band graphs in legend
customPlot->graph(1)->setPen(pen);
Then you can fill in the area between the borders using setChannelFillGraph
:
customPlot->graph(0)->setChannelFillGraph(customPlot->graph(1));
Also don't forget to assign appropriate values for the borders:
QVector<double> x(250);
QVector<double> y0(250), y1(250);
for (int i=0; i<250; ++i)
{
x[i] = i ;
y0[i] = upperValue;
y1[i] = lowerValue;
}
customPlot->graph(0)->setData(x, y0);
customPlot->graph(1)->setData(x, y1);
You can also add other graphs to show some borders, for example in your example.
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