ChartDirector Ver 3.0 (C++ Edition)

Log Scale Axis


  

This example illustrates setting an axis to log scale using Axis.setLogScale3.

Source Code Listing

[The following project is available in "cppdemo/logaxis".]
#include "chartdir.h" void createChart(int img, const char *filename) { //The data for the chart double data[] = {100, 125, 260, 147, 67}; const char *labels[] = {"Mon", "Tue", "Wed", "Thu", "Fri"}; //Create a XYChart object of size 200 x 180 pixels XYChart *c = new XYChart(200, 180); //Set the plot area at (30, 10) and of size 140 x 130 pixels c->setPlotArea(30, 10, 140, 130); //Ise log scale axis if required if (img == 1) { c->yAxis()->setLogScale(); } //Set the labels on the x axis c->xAxis()->setLabels(StringArray(labels, sizeof(labels)/sizeof(*labels))); //Add a color bar layer using the given data. Use a 1 pixel 3D border for //the bars. c->addBarLayer(DoubleArray(data, sizeof(data)/sizeof(*data)), IntArray(0, 0) )->setBorderColor(-1, 1); //output the chart c->makeChart(filename); //free up resources delete c; } int main(int argc, char *argv[]) { createChart(0, "logaxis0.png"); createChart(1, "logaxis1.png"); return 0; }