SciChart.js ships with ~40 JavaScript Chart Examples which you can browse, play with, view the source code and see related documentation. All of this is possible with the SciChart.js Examples Suite, which ships as part of the SciChart.js SDK
Demonstrates how to create a JavaScript Heatmap Chart using SciChart.js, High Performance JavaScript Charts
Demonstrates how to create a JavaScript Heatmap Chart. The FastUniformHeatmapRenderableSeries accepts a 2D array of data and has user-defined color map which can be used to color points by value.