JKQtPlotter/examples/simpletest_filledgraphs/jkqtplotter_simpletest_filledgraphs.cpp
jkriege2 2d08250db6 - added new graph: JKQTPSingleColumnSymbolsGraph
- fixed additional renames JKQTPLotter->JKQTPlotter
- improved documentation (boxplots, JKQTMathText)
- added several examples
2019-01-20 16:15:10 +01:00

105 lines
3.8 KiB
C++

/** \example jkqtplotter_simpletest_filledgraphs.cpp
* Shows how to use filled graphs with JKQTPlotter
*
* \ref JKQTPlotterFilledGraphs
*/
#include <QApplication>
#include "jkqtplotter/jkqtplotter.h"
#include "jkqtplotter/jkqtpgraphsfilledcurve.h"
int main(int argc, char* argv[])
{
QApplication app(argc, argv);
// 1. create a plotter window and get a pointer to the internal datastore (for convenience)
JKQTPlotter plot;
JKQTPDatastore* ds=plot.getDatastore();
// 2. now we create 4 datacolumns with length 256 entries in the datastore
// these will later hold the RGB-histogram and a linear x-values vector
// - the x-values are directly initialized as linear vector 0..255 in 256 steps
// - the other columns are generated and size_t-type indexes are stored for later
// reference to these columns in the graphs-
size_t columnX=ds->addLinearColumn(256, 0, 255, "x");
size_t columnR=ds->addColumn(256, "historam_R");
size_t columnG=ds->addColumn(256, "historam_G");
size_t columnB=ds->addColumn(256, "historam_B");
// - in addition JKQTPColumn objects are generated, which can be used to access
// the data in the columns
JKQTPColumn cG=ds->getColumn(columnG);
JKQTPColumn cR=ds->getColumn(columnR);
JKQTPColumn cB=ds->getColumn(columnB);
// - now all columns for RGB are initialized to 0
cR.setAll(0);
cG.setAll(0);
cB.setAll(0);
// 3. now we open a BMP-file and load it into a QImage
QImage image(":/example.bmp");
// ... and calculate the RGB-histograms
for (int y=0; y<image.height(); y++) {
for (int x=0; x<image.width(); x++) {
QRgb pix=image.pixel(x,y);
cR.incValue(qRed(pix), 1);
cG.incValue(qGreen(pix), 1);
cB.incValue(qBlue(pix), 1);
}
}
// ... and normalize histograms
cR.scale(100.0/static_cast<double>(image.width()*image.height()));
cG.scale(100.0/static_cast<double>(image.width()*image.height()));
cB.scale(100.0/static_cast<double>(image.width()*image.height()));
// 4. now we add three semi-transparent, filled curve plots, one for each histogram
JKQTPFilledCurveXGraph* graphR=new JKQTPFilledCurveXGraph(&plot);
JKQTPFilledCurveXGraph* graphG=new JKQTPFilledCurveXGraph(&plot);
JKQTPFilledCurveXGraph* graphB=new JKQTPFilledCurveXGraph(&plot);
// set graph titles
graphR->set_title("R-channel");
graphG->set_title("G-channel");
graphB->set_title("B-channel");
// set graph colors (lines: non-transparent, fill: semi-transparent) and style
QColor col;
col=QColor("red"); graphR->set_color(col);
col.setAlphaF(0.25); graphR->set_fillColor(col);
col=QColor("green"); graphG->set_color(col);
col.setAlphaF(0.25); graphG->set_fillColor(col);
col=QColor("blue"); graphB->set_color(col);
col.setAlphaF(0.25); graphB->set_fillColor(col);
graphR->set_lineWidth(1);
graphG->set_lineWidth(1);
graphB->set_lineWidth(1);
// set data
graphR->set_xColumn(columnX); graphR->set_yColumn(columnR);
graphG->set_xColumn(columnX); graphG->set_yColumn(columnG);
graphB->set_xColumn(columnX); graphB->set_yColumn(columnB);
// add the graphs to the plot, so they are actually displayed
plot.addGraph(graphB);
plot.addGraph(graphG);
plot.addGraph(graphR);
// 5. set axis labels
plot.get_xAxis()->set_axisLabel("R/G/B-value");
plot.get_yAxis()->set_axisLabel("normalized frequency [%]");
// 4. set the maximum size of the plot to 0..100% and 0..256
plot.setAbsoluteX(0,256);
plot.setAbsoluteY(0,100);
// ... and scale plot automatically
plot.zoomToFit();
// 5. show plotter and make it a decent size
plot.show();
plot.resize(600,400);
return app.exec();
}