/** \example jkqtplotter_simpletest_datastore.cpp * A very basic example for the usage of JKQTPlotter * * \ref JKQTPlottersimpletest_datastore */ #include #include "jkqtplotter/jkqtplotter.h" #include "jkqtplotter/jkqtpgraphsscatter.h" #include "jkqtplotter/jkqtpgraphsimage.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* datastore=plot.getDatastore(); JKQTPXYLineGraph* linegraph; JKQTPColumnMathImage* imggraph; JKQTPXYParametrizedScatterGraph* paramscattergraph; // 2. first we create data inside a QVector for a simple plot (a sine curve) ... and add the plot // note that you could use a std::vector equally well QVector X, Y; const int Ndata=100; for (int i=0; isetXColumn(datastore->addCopiedColumn(X, "x")); linegraph->setYColumn(datastore->addCopiedColumn(Y, "y")); // alternatively you can also tell JKQTPDatastore to just reference an external array: //linegraph->setXColumn(datastore->addColumn(X.data(), X.size(), "x")); //linegraph->setYColumn(datastore->addColumn(Y.data(), Y.size(), "Y")); linegraph->setTitle(QObject::tr("sine graph")); // 3. Now we generate a plot from data in a C-array, just reference in the JKQTPDatastore #define NDATA 5 double XCA[NDATA]= { 1, 2, 3, 4, 5 }; double YCA[NDATA]= { 1, 0, 1, 0, 1 }; plot.addGraph(linegraph=new JKQTPXYLineGraph(&plot)); linegraph->setXColumn(datastore->addColumn(XCA, NDATA, "xca (C-array)")); linegraph->setYColumn(datastore->addColumn(YCA, NDATA, "yca (C-array)")); // of course you could also simply copy the data with a comparable syntax: //linegraph->setXColumn(datastore->addCopiedColumn(XCA, NDATA, "xca (C-array)")); //linegraph->setYColumn(datastore->addCopiedColumn(YCA, NDATA, "yca (C-array)")); linegraph->setTitle(QObject::tr("linked C-array data")); // 4. Since graphs often display (x,y)-pairs, it may make sense to store them in a map (e.g. for histograms) // There there are also functions that copy the contents of a map into a JKQTPDatastore, resulting in // two columns beeing added: std::map datamap; datamap[1]=1.1; datamap[2]=1.4; datamap[4]=1.2; datamap[5]=1.8; datamap[7]=0.9; plot.addGraph(linegraph=new JKQTPXYLineGraph(&plot)); linegraph->setXYColumns(datastore->addCopiedMap(datamap, "map_x", "map_y")); linegraph->setTitle(QObject::tr("copied map")); // 5. It is also possible to leave the data mangement completely to the JKQTPDatastore // and just edit the data with access functions from JKQTPDatastore: plot.addGraph(linegraph=new JKQTPXYLineGraph(&plot)); // 5.1 this adds a column with 40 values, linearly spaced between 0 and 20 (inclusive). size_t colLinX=datastore->addLinearColumn(40, 0, 20, "x_lin"); // 5.2 this adds a column with one entry for every entry x in the column colLinX, where // the entry is calculated by applying a function cos(x)*x/20.0 size_t colFunc1=datastore->addColumnCalculatedFromColumn(colLinX, [](double x)->double { return cos(x)*x/20.0; }, "cos(x_lin)*x_lin/20.0"); // the same can be done by this code explicitly: // 5.2.1 add a column with as many rows as column colLinX //size_t colFunc1=datastore->addColumn(datastore->getRows(colLinX), "cos(x_lin)*x_lin/20.0"); // 5.2.2 iterate over the data in column colLinX and set a newly calculated value into a row of column colFunc1 //for (size_t i=0; igetRows(colLinX); i++) { // double x=datastore->get(colLinX, i); // datastore->set(colFunc1, i, cos(x)*x/20.0); //} linegraph->setXColumn(colLinX); linegraph->setYColumn(colFunc1); linegraph->setTitle(QObject::tr("calculated column(s)")); // 6. The function addLinearGridColumns() generates a rectangular 2D grid of coordinates // in row-major order. Here we generate a 10x10 grid with x-coordinates between 10 and 20 (inclusive) // and y-coordinates between 1.5 and 3: std::pair colLinXY=datastore->addLinearGridColumns(10, 10, 20, 10, 1.5, 3); // now we can add another column with 10*10=100 entries and fill it with some values // calculated from the the x and y-values in colLinXY: size_t imgColumn=datastore->addImageColumn(10, 10, "image values"); for (size_t i=0; igetRows(imgColumn); i++) { double x=datastore->get(colLinXY.first, i); double y=datastore->get(colLinXY.second, i); datastore->set(imgColumn, i, cos((x-15.0))/(x-15.0)*cos((y-2.0))/(x-2.0)); } // alternatively you can access image pixels with setPixel(): //for (int iy=0; iy<10; iy++) { // for (int ix=0; ix<10; ix++) { // datastore->setPixel(imgColumn, ix, iy, sin(ix*iy/30.0)); // } //} // the loop above can be written more compact using addColumnCalculatedFromColumn(): //imgColumn=datastore->addColumnCalculatedFromColumn(colLinXY.first, colLinXY.second, [](double x, double y)->double { return cos((x-15.0))/(x-15.0)*cos((y-2.0))/(x-2.0); }, "image value"); // finally we can use a JKQTPXYParametrizedScatterGraph to display the data from our three columns // by using colLinXY->first and colLinXY->second as positions for symbols that are colored, based // on the respective value in imgColumn: plot.addGraph(paramscattergraph=new JKQTPXYParametrizedScatterGraph(&plot)); paramscattergraph->setXYColumns(colLinXY); paramscattergraph->setColorColumn(imgColumn); paramscattergraph->setTitle(QObject::tr("parametrized scatter")); // alternatively you can only use the column imgColumn in a JKQTPColumnMathImage plot.addGraph(imggraph=new JKQTPColumnMathImage(&plot)); imggraph->setImageColumn(imgColumn); imggraph->setX(21); imggraph->setY(1.5); imggraph->setWidth(10); imggraph->setHeight(1.5); imggraph->setTitle(QObject::tr("imgColumn")); // 6. autoscale the plot so the graph is contained plot.zoomToFit(); // show plotter and make it a decent size plot.show(); plot.resize(600,400); return app.exec(); }