ChartDirector Ver 3.0 (C++ Edition)

Scatter Trend Chart




The chart in this example composed of four layers - 2 scatter layers created using XYChart.addScatterLayer, and two trend line layer created using XYChart.addTrendLayer2.

Source Code Listing

[The following project is available in "cppdemo/scattertrend".]
#include "chartdir.h" int main(int argc, char *argv[]) { //The XY data of the first data series double dataX0[] = {50, 55, 37, 24, 42, 49, 63, 72, 83, 59}; double dataY0[] = {3.6, 2.8, 2.5, 2.3, 3.8, 3.0, 3.8, 5.0, 6.0, 3.3}; //The XY data of the second data series double dataX1[] = {50, 55, 37, 24, 42, 49, 63, 72, 83, 59}; double dataY1[] = {1.6, 1.8, 0.8, 0.5, 1.3, 1.5, 2.3, 2.4, 2.9, 1.5}; //Create a XYChart object of size 450 x 420 pixels XYChart *c = new XYChart(450, 420); //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 point Times Bold Itatic font. c->addTitle("Server Performance", "timesbi.ttf", 18); //Add a title to the y axis using 12 pts Arial Bold Italic font c->yAxis()->setTitle("Response Time (sec)", "arialbi.ttf", 12); //Set the y axis line width to 3 pixels c->yAxis()->setWidth(3); //Set the y axis label format to show 1 decimal point c->yAxis()->setLabelFormat("{value|1}"); //Add a title to the x axis using 12 pts Arial Bold Italic font c->xAxis()->setTitle("Server Load (TPS)", "arialbi.ttf", 12); //Set the x axis line width to 3 pixels c->xAxis()->setWidth(3); //Add a scatter layer using (dataX0, dataY0) c->addScatterLayer(DoubleArray(dataX0, sizeof(dataX0)/sizeof(*dataX0)), DoubleArray(dataY0, sizeof(dataY0)/sizeof(*dataY0)), "Server AAA", DiamondSymbol, 11, 0x8000); //Add a trend line layer for (dataX0, dataY0) c->addTrendLayer(DoubleArray(dataX0, sizeof(dataX0)/sizeof(*dataX0)), DoubleArray(dataY0, sizeof(dataY0)/sizeof(*dataY0)), 0x8000 )->setLineWidth(3); //Add a scatter layer for (dataX1, dataY1) c->addScatterLayer(DoubleArray(dataX1, sizeof(dataX1)/sizeof(*dataX1)), DoubleArray(dataY1, sizeof(dataY1)/sizeof(*dataY1)), "Server BBB", TriangleSymbol, 9, 0x6666ff); //Add a trend line layer for (dataX1, dataY1) c->addTrendLayer(DoubleArray(dataX1, sizeof(dataX1)/sizeof(*dataX1)), DoubleArray(dataY1, sizeof(dataY1)/sizeof(*dataY1)), 0x6666ff )->setLineWidth(3); //output the chart c->makeChart("scattertrend.png"); //free up resources delete c; return 0; }