Do you mean like in the
https://www.qcustomplot.com/index.php/demos/advancedaxesdemo
demo, the left axis? Or really on top of each other? you could try playing with the setOffset or perhaps modifying the QCPAxis to report a minimum margin of 0.
Thanks for the reply.
When adding a new valueAxis, the axes are horizontally layed out, allowing graphs to use the whole height of the axisRect.
I would like to lay out value axes vertically.
The closest examples of what i want to achieve are seismogram or F1 lap telemetry plot.
I already tried to hack qcp and achieved to set the axis height and position, but before going further, just want to know if someone has faced this need and found a nice solution.
I managed to quickly do what i want.
Here is the result : https://postimg.cc/ZWRGQbFV/84b3bc7a
To do so, i create fake visible axes aligned vertically in a QCPLayoutGrid.
For each graph, we need to create specific hidden axis.
And after updating the layout, the ranges of hidden axes are calculated based on the range/height/position of the associated fake axis.
Code balow, based on the plot-examples project :
void MainWindow::setupStackedAxis(QCustomPlot *customPlot)
{
demoName = "Stacked Axes Demo";
customPlot->plotLayout()->clear(); // clear default axis rect so we can start from scratch
QCPAxisRect *wideAxisRect = new QCPAxisRect(customPlot, false);
wideAxisRect->setMinimumMargins(QMargins(15, 15, 5, 15));
wideAxisRect->setupFullAxesBox(true);
wideAxisRect->axis(QCPAxis::atLeft)->setVisible(false);
wideAxisRect->axis(QCPAxis::atTop)->setVisible(false);
wideAxisRect->axis(QCPAxis::atRight)->grid()->setVisible(true);
wideAxisRect->axis(QCPAxis::atBottom)->grid()->setVisible(true);
QCPLayoutGrid *subLayout = new QCPLayoutGrid;
subLayout->setFillOrder(QCPLayoutGrid::foRowsFirst);
customPlot->plotLayout()->addElement(0, 0, wideAxisRect); // insert axis rect in first row
customPlot->plotLayout()->addElement(0, 1, subLayout); // sub layout in second row (grid layout will grow accordingly)
customPlot->plotLayout()->setColumnStretchFactor(0,1);
customPlot->plotLayout()->setColumnStretchFactor(1, 0.001);
// create fake axis
QCPAxisRect *subRectTop = new QCPAxisRect(customPlot, false);
auto topAxis = subRectTop->addAxis(QCPAxis::atRight);
topAxis->setTickLabelColor(Qt::blue);
topAxis->setTickPen(QPen(Qt::blue));
topAxis->setSubTickPen(QPen(Qt::blue));
topAxis->setBasePen(QPen(Qt::blue));
topAxis->ticker()->setTickCount(3);
subRectTop->setMinimumSize(0,0);
subRectTop->setMinimumMargins(QMargins(5, 15, 40, 5));
subLayout->addElement(subRectTop);
//Create real axis - not visible
auto firstAxis = wideAxisRect->addAxis(QCPAxis::atRight);
firstAxis->setVisible(false);
QCPAxisRect *subRectMiddle = new QCPAxisRect(customPlot, false);
auto middleAxis = subRectMiddle->addAxis(QCPAxis::atRight);
middleAxis->setTickLabelColor(Qt::red);
middleAxis->setTickPen(QPen(Qt::red));
middleAxis->setSubTickPen(QPen(Qt::red));
middleAxis->setBasePen(QPen(Qt::red));
middleAxis->ticker()->setTickCount(3);
subRectMiddle->setMinimumSize(0,0);
subRectMiddle->setMinimumMargins(QMargins(5, 5, 40, 5));
subLayout->addElement(subRectMiddle);
auto secondAxis = wideAxisRect->addAxis(QCPAxis::atRight);
secondAxis->setVisible(false);
QCPAxisRect *subRectBottom = new QCPAxisRect(customPlot, false);
auto bottomAxis = subRectBottom->addAxis(QCPAxis::atRight);
bottomAxis->setTickLabelColor(Qt::green);
bottomAxis->setTickPen(QPen(Qt::green));
bottomAxis->setSubTickPen(QPen(Qt::green));
bottomAxis->setBasePen(QPen(Qt::green));
bottomAxis->ticker()->setTickCount(3);
subRectBottom->setMinimumSize(0,0);
subRectBottom->setMinimumMargins(QMargins(5, 5, 40, 15));
subLayout->addElement(subRectBottom);
auto thirdAxis = wideAxisRect->addAxis(QCPAxis::atRight);
thirdAxis->setVisible(false);
foreach (QCPAxisRect *rect, customPlot->axisRects())
{
foreach (QCPAxis *axis, rect->axes())
{
axis->setLayer("axes");
axis->grid()->setLayer("grid");
}
}
QCPGraph *graphCosFirst = customPlot->addGraph(wideAxisRect->axis(QCPAxis::atBottom), firstAxis);
graphCosFirst->setPen(QPen(Qt::blue));
QCPGraph *graphCosSecond = customPlot->addGraph(wideAxisRect->axis(QCPAxis::atBottom), secondAxis);
graphCosSecond->setPen(QPen(Qt::red));
QCPGraph *graphCosThird = customPlot->addGraph(wideAxisRect->axis(QCPAxis::atBottom), thirdAxis);
graphCosThird->setPen(QPen(Qt::green));
QVector<QCPGraphData> dataCos(51);
for (int i=0; i<dataCos.size(); ++i)
{
auto key = i/(double)(dataCos.size()-1)*10-5.0;
auto value = qCos(key);
graphCosFirst->addData(key, value);
graphCosSecond->addData(key, value);
graphCosThird->addData(key, value);
}
wideAxisRect->axis(QCPAxis::atBottom)->rescale();
topAxis->setRange(0,1);
middleAxis->setRange(-0.5,0.5);
bottomAxis->setRange(-2,0);
QCPMarginGroup *marginGroup = new QCPMarginGroup(customPlot);
subRectTop->setMarginGroup(QCP::msTop, marginGroup);
subRectBottom->setMarginGroup(QCP::msBottom, marginGroup);
wideAxisRect->setMarginGroup(QCP::msTop | QCP::msBottom, marginGroup);
connect(customPlot, &QCustomPlot::afterLayout, this, [=](){
{
auto pixelRatio = topAxis->range().size() / (topAxis->coordToPixel(topAxis->range().lower) - topAxis->coordToPixel(topAxis->range().upper));
auto topOffset = (topAxis->coordToPixel(topAxis->range().upper) - wideAxisRect->rect().top()) * pixelRatio;
auto bottomOffset = (wideAxisRect->rect().bottom() - topAxis->coordToPixel(topAxis->range().lower)) * pixelRatio;
firstAxis->setRange(topAxis->range().lower - bottomOffset,
topAxis->range().upper + topOffset);
}
{
auto pixelRatio = middleAxis->range().size() / (middleAxis->coordToPixel(middleAxis->range().lower) - middleAxis->coordToPixel(middleAxis->range().upper));
auto topOffset = (middleAxis->coordToPixel(middleAxis->range().upper) - wideAxisRect->rect().top()) * pixelRatio;
auto bottomOffset = (wideAxisRect->rect().bottom() - middleAxis->coordToPixel(middleAxis->range().lower)) * pixelRatio;
secondAxis->setRange(middleAxis->range().lower - bottomOffset,
middleAxis->range().upper + topOffset);
}
{
auto pixelRatio = bottomAxis->range().size() / (bottomAxis->coordToPixel(bottomAxis->range().lower) - bottomAxis->coordToPixel(bottomAxis->range().upper));
auto topOffset = (bottomAxis->coordToPixel(bottomAxis->range().upper) - wideAxisRect->rect().top()) * pixelRatio;
auto bottomOffset = (wideAxisRect->rect().bottom() - bottomAxis->coordToPixel(bottomAxis->range().lower)) * pixelRatio;
thirdAxis->setRange(bottomAxis->range().lower - bottomOffset,
bottomAxis->range().upper + topOffset);
}
});
}