Examples

Basic heat map

The following code will produce a very basic heat map saved as a .png file.  Although this is a very simple example, more advanced cases are not much more complex. Simply expand step 2 to set other parameters such as the colour range, title font, axis values or any of the many other configuration options.

// Create some dummy data.
double[][] data = new double[][]{{3,2,3,4,5,6},
                                 {2,3,4,5,6,7},
                                 {3,4,5,6,7,6},
                                 {4,5,6,7,6,5}};

// Step 1: Create our heat map chart using our data.
HeatChart map = new HeatChart(data);

// Step 2: Customise the chart.
map.setTitle("This is my heat chart title");
map.setXAxisLabel("X Axis");
map.setYAxisLabel("Y Axis");

// Step 3: Output the chart to a file.
map.saveToFile(new File("java-heat-chart.png"));

This code should produce the following heat map image. Note that by default the colour range is greyscale, for more interesting images you can use the setHighValueColour(Color) and setLowValueColour(Color) methods.

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