mirror of
https://github.com/jkriege2/JKQtPlotter.git
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105 lines
3.5 KiB
C++
105 lines
3.5 KiB
C++
/** \example speedtestplot.cpp
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* JKQTPlotter: Examples: Simple line-graph with live-data (speed test)
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*
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* \ref JKQTPlotterSpeedTest
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*/
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#include "speedtestplot.h"
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#include "jkqtplotter/graphs/jkqtpscatter.h"
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SpeedTestPlot::SpeedTestPlot():
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JKQTPlotter(), dx(1.0/double(NDATA)*4.0*M_PI), x0(0)
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{
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// 1. optimize JKQTPlotter for speed (by switching off anti-aliasing)
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getPlotter()->setUseAntiAliasingForGraphs(false);
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getPlotter()->setUseAntiAliasingForSystem(false);
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getPlotter()->setUseAntiAliasingForText(false);
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// 2. now we create data for a simple plot (a sine curve + random[-0.5,0.5])
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for (size_t i=0; i<NDATA; i++) {
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const double x=static_cast<double>(i)*dx;
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X[i]=x0+x;
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Y[i]=sin(x)+static_cast<double>(std::rand())/static_cast<double>(RAND_MAX + 1u)-0.5;
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Y2[i]=cos(x)+static_cast<double>(std::rand())/static_cast<double>(RAND_MAX + 1u)-0.5;
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}
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// 3. make data available to JKQTPlotter by adding it to the internal datastore.
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// Here the data from the std::array's is not copied, but only the pointer to
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// the array is added to the datastore. therefore the datastore does not manage
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// the memory, oly uses the data stored in it!
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JKQTPDatastore* ds=getDatastore();
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size_t columnX=ds->addColumn(X.data(), X.size(), "x");
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size_t columnY=ds->addColumn(Y.data(), Y.size(), "y");
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size_t columnY2=ds->addColumn(Y2.data(), Y2.size(), "y2");
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// 4. create two graphs in the plot, which plots the dataset X/Y:
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JKQTPXYLineGraph* graph=new JKQTPXYLineGraph(this);
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graph->setXColumn(columnX);
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graph->setYColumn(columnY);
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graph->setTitle(QObject::tr("live sin() graph"));
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graph->setLineWidth(1);
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addGraph(graph);
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JKQTPXYLineGraph* graph2=new JKQTPXYLineGraph(this);
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graph2->setXColumn(columnX);
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graph2->setYColumn(columnY2);
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graph2->setTitle(QObject::tr("live cos() graph"));
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graph2->setLineWidth(1);
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addGraph(graph2);
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// 6. scale the plot so the graph is contained
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setX(X[0], X[NDATA-1]);
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setY(-2,2);
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// show plotter and make it a decent size
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show();
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resize(1000,500);
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}
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SpeedTestPlot::~SpeedTestPlot()
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{
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}
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void SpeedTestPlot::plotNewData()
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{
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// move old data to the left
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for (size_t i=0; i<NDATA-1; i++) {
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X[i]=X[i+1];
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Y[i]=Y[i+1];
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Y2[i]=Y2[i+1];
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}
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// add one new data point
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X[NDATA-1]=X[NDATA-2]+dx;
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Y[NDATA-1]=sin(X[NDATA-1])+static_cast<double>(std::rand())/static_cast<double>(RAND_MAX + 1u)-0.5;
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Y2[NDATA-1]=cos(X[NDATA-1])+static_cast<double>(std::rand())/static_cast<double>(RAND_MAX + 1u)-0.5;
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/*
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// ALTERNATIVE: MOVE data, but keep x-axis range
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x0+=dx;
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for (size_t i=0; i<NDATA-1; i++) {
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Y[i]=Y[i+1];
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Y2[i]=Y2[i+1];
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}
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// add one new data point
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Y[NDATA-1]=sin(X[NDATA-1]+x0)+static_cast<double>(std::rand())/static_cast<double>(RAND_MAX + 1u)-0.5;
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Y2[NDATA-1]=cos(X[NDATA-1]+x0)+static_cast<double>(std::rand())/static_cast<double>(RAND_MAX + 1u)-0.5;
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*/
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// set new x-range and replot
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setX(X[0], X[NDATA-1]);
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redrawPlot();
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// calculate and update FPS-rate in window title
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auto tlastalst=t_lastplot;
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t_lastplot=std::chrono::system_clock::now();
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double delta_secs=static_cast<double>(std::chrono::duration_cast<std::chrono::milliseconds>(t_lastplot-tlastalst).count())/1000.0;
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setWindowTitle(QString("Live Data Speed Test: %2 datapoint, %1 fps").arg(1/delta_secs).arg(NDATA));
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// enqueue call for next data value
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QTimer::singleShot(1, this, SLOT(plotNewData()));
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}
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