Heat map charting library for Java (documentation)

 The JHeatChart library provides a simple API for generating Java heat maps.
 Output heat maps as .png, .jpg or .gif images. Generate Image objects for
 further processing. Show generated Image in a Swing JPanel. Fully customisable
 colours, dimensions, fonts etc. Linear, logarithmic and exponential
 colour scales.
 .
 This package includes the JHeatChart API javadocs.