Plot Screenshots: Parametric Curves Demo
// create empty curve objects:
QCPCurve *fermatSpiral1 = new QCPCurve(customPlot->xAxis, customPlot->yAxis);
QCPCurve *fermatSpiral2 = new QCPCurve(customPlot->xAxis, customPlot->yAxis);
QCPCurve *deltoidRadial = new QCPCurve(customPlot->xAxis, customPlot->yAxis);
// generate the curve data points:
const int pointCount = 500;
QVector<QCPCurveData> dataSpiral1(pointCount), dataSpiral2(pointCount), dataDeltoid(pointCount);
for (int i=0; i<pointCount; ++i)
{
double phi = i/(double)(pointCount-1)*8*M_PI;
double theta = i/(double)(pointCount-1)*2*M_PI;
dataSpiral1[i] = QCPCurveData(i, qSqrt(phi)*qCos(phi), qSqrt(phi)*qSin(phi));
dataSpiral2[i] = QCPCurveData(i, -dataSpiral1[i].key, -dataSpiral1[i].value);
dataDeltoid[i] = QCPCurveData(i, 2*qCos(2*theta)+qCos(1*theta)+2*qSin(theta), 2*qSin(2*theta)-qSin(1*theta));
}
// pass the data to the curves; we know t (i in loop above) is ascending, so set alreadySorted=true (saves an extra internal sort):
fermatSpiral1->data()->set(dataSpiral1, true);
fermatSpiral2->data()->set(dataSpiral2, true);
deltoidRadial->data()->set(dataDeltoid, true);
// color the curves:
fermatSpiral1->setPen(QPen(Qt::blue));
fermatSpiral1->setBrush(QBrush(QColor(0, 0, 255, 20)));
fermatSpiral2->setPen(QPen(QColor(255, 120, 0)));
fermatSpiral2->setBrush(QBrush(QColor(255, 120, 0, 30)));
QRadialGradient radialGrad(QPointF(310, 180), 200);
radialGrad.setColorAt(0, QColor(170, 20, 240, 100));
radialGrad.setColorAt(0.5, QColor(20, 10, 255, 40));
radialGrad.setColorAt(1,QColor(120, 20, 240, 10));
deltoidRadial->setPen(QPen(QColor(170, 20, 240)));
deltoidRadial->setBrush(QBrush(radialGrad));
// set some basic customPlot config:
customPlot->setInteractions(QCP::iRangeDrag | QCP::iRangeZoom | QCP::iSelectPlottables);
customPlot->axisRect()->setupFullAxesBox();
customPlot->rescaleAxes();