Feature Intersect Heat Map

[rbossio]

I want to highlight where 2 (or more but will start with 2) feature sets intercept the most (based on feature count) on a map.

For example, I have a layer with features with a unique value attribute (entity identifier).

The first entity is found in Chicago (100 features), San Francisco (300 features), and New your (500 features).

The second entity is found in Chicago (50 features), San Francisco (300 features) and New York (100 features).

In this example, I'd like to see San Francisco red hot (0%), Chicago warm (66.67%), and New York cool (133.33%) - using percentage difference (or other calculation more fitting this example).

Also, as I zoom into any area, the heat map should persist to highlight where there is most/least overlap.

Is this possible? I tried looking at various renderers but have not found the one that quite fits this scenario. Maybe there is one that just has to be setup correctly? 

Any info appreciated. Thanks!

[KristianEkenes]

You can't render data from two layers or datasets in a single visualization. All data must be part of the same layer. You can create a new layer that contains all the data and have a field grouping each feature two each set as described above. Then you can render that new layer with something like heatmap or another renderer type.

[rbossio]

Kristian - All the features are in one layer/dataset. Each "set" is identified by a unique identifier. I tried using a heat map with a UniqueValueRenderer. The problem is, if one "set" has many features in one area, it will show hot, even though the second "set" has no features in the area. I need the renderer to base hot/cold on the presence of both "set".

[KristianEkenes]

Ah ok. What is the final goal of the visual in your mind? Do you want to show a heatmap where areas that have a raster surface show as hot, and cold areas have very little or no heatmap? Or do you want everything to be along a surface so hot areas are for example very red, and cold areas are very blue? In that scenario everything is part of the surface?

[rbossio]

Originally, I have simple circle symbol for all features. Say, first "set" is blue, second "set" is green. As the two sets merge on the map, they "cluster" or "glow".  It should highlight to the user that there is little (individual symbols/glow blue) to allot (cluster/glow red) of intersection between the two sets. As you zoom in, you continue to see that cold/hot heat map until you zoom in enough to see the individual features (blue/green symbols). In my original example, you would see 3 heat "zones" when zoomed out to the entire US map, SF hot (high glow/red glow), Chicago warm (mod glow/yellow glow), and NY cold (low glow/blue glow). This focuses the user's attention to SF, and as they zoom in, they see that same hot/cold going down to city area, neighborhoods, blocks, street, until you seeing the individual features again. 

I don't know if that's the best description but basically I'd like to see the behavior of heat map but the "level of feature overlap" (however that can be calculated) between the two "sets" determines hot/cold in the heat map, not just overall feature count. I want to draw attention to where the two sets intersect the most when zoomed out, and eventually get back to the features themselves as you zoom in.

[rbossio]

Bump! Trying to get any feedback on this. Thanks.