topic Re: How to create comparative heatmaps in ArcGIS Online Questions

How to create comparative heatmaps

elterrell4 — Wed, 16 Jun 2021 20:45:27 GMT

I've created 3 heat maps using kernel density and want the classification/range/color scheme to be consistent across all 3. One of them has much higher numbers.

Map 1: (9 classes) goes 1 - 1607

Map 2: (9 classes) goes 1 - 282

Map 3: (9 classes) goes 1 - 337

I've tried manually entering them. When I manually enter for map 1, I use break values/increments of 200. When I try and do that with map 2 and 3, it won't allow me to enter 200 as the second break and in fact changes a break farther down to 200.

If I can't get the color scheme and the break values consistent, the heatmaps won't be any good for comparing year to year.

Any suggestions?

Re: How to create comparative heatmaps

DavidPike — Thu, 17 Jun 2021 19:28:53 GMT

Generally you'd use the class break/intervals of the feature/raster with the largest range, which is correct.

However your intervals of 200 will only give you 2 classes in maps 2 and 3. If that's what you're happy with then the only issue is that I don't think you can't set a class break beyond the maximum value of the raster. A simple solution will be to change the label in the legend from say 201 - 236 -> 201 - 400 (although this is against my opinion that the legend class should not be deceptive in it's maximum value).

For ease, what I generally have done in the same situation is to save Map 1's symbology into a layer file, then use that layer file to symbolise the other rasters. Properties->Symbology->Import from layer file.

Re: How to create comparative heatmaps

elterrell4 — Mon, 21 Jun 2021 14:04:23 GMT

Worked perfect, thank you David.