A heat-map according to the definition found in Wikipedia is "a graphical representation of data where the values taken by a variable in a two-dimensional map are represented as colors." This representation is used to quickly interpret a potentially large number of values in what can be sizable grid of values. Heat-maps are used to find hot-spots and cool areas – to determine for example deviations from the average or threshold value.

This article shows how the PivotTable in the ADF 11g RichFaces Data Visualization Tags library can be used to create such a Heat Map. In just a small number of simple steps, this heat-map can be realized. We will see this in an example: a heat-map based on the grid of Job vs. Department with average Salary in the cells. The heat-map should quickly tell us which jobs and which departments pay well or lousy.

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