charleslaw / go-heatmapper

Heatmapper

This is a fork of the go-heatmaps project but with the addition of 2 features that break the API:

• Ability to specify extent of the heatmap using the same coordinate sytem as the input points
• Support for weighted points

Heatmaps

This is a toolkit for creating heatmaps. Heatmaps are awesome. I use them for a few things, and now you can, too.

There are quite a few things you can do here and they don't all have the high level documentation they deserve currently. You can start by looking at the example to get a feel for what you can do. Basically, feed in a bunch of x,y type data and get back a heatmap. Awesome.

Here's an example from a real-live report:

Colors

Colors are always the hardest part, so I attempted to make it easy by providing three things:

Predefined Color Schemes

gheat has a set of colors that are available by default under the schemes subpackage. You can preview them in their documentation and use them directly.

Drawing Color Schemes

The schemes subpackage also has a tool for generating a color scheme from an image. Given an image that looks like this:

You can use schemes.FromImage("/path/to/file") to load it and use it directly. Colors near the bottom are for sparsely populated areas and colors near the top are for areas that are densely populated.

Computing Color Schemes

You can also compute a color scheme from spec using schemes.Build. This lets you specify starting and ending colors across multiple segments. Fun away!