> For the complete documentation index, see [llms.txt](https://vikram-bajaj.gitbook.io/cs-gy-6313-information-visualization/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://vikram-bajaj.gitbook.io/cs-gy-6313-information-visualization/main-5/geo-visualization/geo-visualization-techniques/heat-maps.md).

# Heat Maps

Heat Maps are used to depict **continuous values** that are typically obtained using a *density estimation* method that estimates a continuous density model from discrete data.

Appropriate use and design of color scales is crucial for heat maps. (The rainbow color map should be avoided because it tries to represent a quantity (continuous value) through different hues, which has the unintended impact of categorization. The human eye only uses intensity to comprehend a continuous value). Perceptually uniform color scales should be used. [Color Brewer](http://colorbrewer2.org) is a good source for such scales. Matplotlib also has decent color scales.