ChartDirector 6.0 (C++ Edition)

Vector Chart

This example demonstrates a vector chart.

A vector chart is like a scatter chart, but the symbols are arrows which can be of arbitrary lengths pointing to arbitrary directions. Thus each symbol in a vector chart is specified by 4 values - the x and y coordinates, the length and the direction.

In ChartDirector, an XY vector layer is created using XYChart.addVectorLayer.

Source Code Listing

[The following code is available in "cppdemo/vector". A MFC version of the code is available in "mfcdemo/mfcdemo" (Windows edition only). A QT version of the code is available in "qtdemo/qtdemo".]
 ```#include "chartdir.h" int main(int argc, char *argv[]) { // The (x, y) coordinates of the starting point of the vectors double dataX[] = {20, 40, 60, 80, 100, 20, 40, 60, 80, 100, 20, 40, 58, 62, 80, 100, 20, 40, 60, 80, 100, 20, 40, 60, 80, 100}; double dataY[] = {20, 20, 20, 20, 20, 40, 40, 40, 40, 40, 60, 60, 60, 60, 60, 60, 80, 80, 80, 80, 80, 100, 100, 100, 100, 100}; // The lengths (radii) and directions (angles) of the vectors double dataR[] = {6, 6, 9, 6, 6, 6, 9, 12, 9, 6, 9, 12, 12, 12, 12, 9, 6, 9, 12, 9, 6, 6, 6, 9, 6, 6}; double dataA[] = {-45, -30, 0, 30, 45, -60, -45, 0, 45, 60, -90, -90, -90, 90, 90, 90, -120, -135, 180, 135, 120, -135, -150, 180, 150, 135}; // Create a XYChart object of size 450 x 390 pixels XYChart *c = new XYChart(450, 390); // Set the plotarea at (55, 40) and of size 350 x 300 pixels, with a light grey border // (0xc0c0c0). Turn on both horizontal and vertical grid lines with light grey color (0xc0c0c0) c->setPlotArea(55, 40, 350, 300, -1, -1, 0xc0c0c0, 0xc0c0c0, -1); // Add a title to the chart using 18pt Times Bold Itatic font. c->addTitle("Vector Chart Demonstration", "timesbi.ttf", 18); // Add a title to the y axis using 12pt Arial Bold Italic font c->yAxis()->setTitle("Y Axis Title", "arialbi.ttf", 12); // Add a title to the x axis using 12pt Arial Bold Italic font c->xAxis()->setTitle("X Axis Title", "arialbi.ttf", 12); // Set the axes line width to 3 pixels c->xAxis()->setWidth(3); c->yAxis()->setWidth(3); // Add a vector layer to the chart using blue (0000CC) color, with vector arrow size set to 11 // pixels c->addVectorLayer(DoubleArray(dataX, (int)(sizeof(dataX) / sizeof(dataX[0]))), DoubleArray( dataY, (int)(sizeof(dataY) / sizeof(dataY[0]))), DoubleArray(dataR, (int)(sizeof(dataR) / sizeof(dataR[0]))), DoubleArray(dataA, (int)(sizeof(dataA) / sizeof(dataA[0]))), Chart::YAxisScale, 0x0000cc)->setArrowHead(11); // Output the chart c->makeChart("vector.png"); //free up resources delete c; return 0; }```