ChartDirector Ver 3.0 (C++ Edition)

Arbitrary XY Line Chart




This example demostrates drawing a line chart with arbitrary x coordinates (not monotonically increasing or decreasing). The x values of the data points are passed to ChartDirector using Layer.setXData.

Note this chart contains labels for the start and end points of the line. They are created using Layer.addCustomDataLabel.

Source Code Listing

[The following project is available in "cppdemo/xyline".]
#include "chartdir.h" int main(int argc, char *argv[]) { //The (x, y) data for the first line double dataX0[] = {20, 90, 40, 30, 12}; double dataY0[] = {10, 40, 75, 54, 20}; //The (x, y) data for the second line double dataX1[] = {10, 40, 75, 54, 60}; double dataY1[] = {50, 90, 40, 30, 10}; //Create a XYChart object of size 450 x 450 pixels XYChart *c = new XYChart(450, 450); //Set the plotarea at (55, 65) and of size 350 x 300 pixels, with white //background and a light grey border (0xc0c0c0). Turn on both horizontal and //vertical grid lines with light grey color (0xc0c0c0) c->setPlotArea(55, 65, 350, 300, 0xffffff, -1, 0xc0c0c0, 0xc0c0c0, -1); //Add a legend box at (50, 30) (top of the chart) with horizontal layout. //Use 12 pts Times Bold Italic font. Set the background and border color to //Transparent. c->addLegend(50, 30, false, "timesbi.ttf", 12)->setBackground(Transparent); //Add a title to the chart using 18 pts Times Bold Itatic font c->addTitle("Reaction Path", "timesbi.ttf", 18); //Add a title to the y axis using 12 pts Arial Bold Italic font c->yAxis()->setTitle("Temperature (Celcius)", "arialbi.ttf", 12); //Set the y axis line width to 3 pixels c->yAxis()->setWidth(3); //Add a title to the x axis using 12 pts Arial Bold Italic font c->xAxis()->setTitle("Pressure (Pa)", "arialbi.ttf", 12); //Set the x axis line width to 3 pixels c->xAxis()->setWidth(3); //Add a red (0xff3333) line layer using dataX0 and dataY0 LineLayer *layer1 = c->addLineLayer(DoubleArray(dataY0, sizeof(dataY0)/sizeof(*dataY0)), 0xff3333, "Compound AAA"); layer1->setXData(DoubleArray(dataX0, sizeof(dataX0)/sizeof(*dataX0))); //Set the line width to 3 pixels layer1->setLineWidth(3); //Use 9 pixel square symbols for the data points layer1->getDataSet(0)->setDataSymbol(SquareSymbol, 9); //Add custom text labels to the first and last point on the scatter plot //using Arial Bold font layer1->addCustomDataLabel(0, 0, "Start", "arialbd.ttf"); layer1->addCustomDataLabel(0, 4, "End", "arialbd.ttf"); //Add a green (0x33ff33) line layer using dataX1 and dataY1 LineLayer *layer2 = c->addLineLayer(DoubleArray(dataY1, sizeof(dataY1)/sizeof(*dataY1)), 0x33ff33, "Compound BBB"); layer2->setXData(DoubleArray(dataX1, sizeof(dataX1)/sizeof(*dataX1))); //Set the line width to 3 pixels layer2->setLineWidth(3); //Use 11 pixel diamond symbols for the data points layer2->getDataSet(0)->setDataSymbol(DiamondSymbol, 11); //Add custom text labels to the first and last point on the scatter plot //using Arial Bold font layer2->addCustomDataLabel(0, 0, "Start", "arialbd.ttf"); layer2->addCustomDataLabel(0, 4, "End", "arialbd.ttf"); //output the chart c->makeChart("xyline.png"); //free up resources delete c; return 0; }