Feature request #9124
Heatmap in percentage
|Assigned to:||-||% Done:||
|Target version:||Version 3.0|
|Platform version:||Pull Request or Patch supplied:||No|
Heatmaps would be far more convenient (easier to interpret in many contexts) if they could (optionally) be expressed in % rather than in absolute values (in inverse values, so one could create isolines including, say, 95% probability). The change seems trivial:
- calculate the maximum
- dividing the raster values by that
- adding an option to choose between absolute values and %
Also a note on the help on how to interpret cell values would make life easier for newbies.
Updated by Nyall Dawson over 3 years ago
It's actually not quite that simple - the maximum value is not known until the entire heatmap is generated, it can't be calculated in advance.
The actual process would be:
1. Generate the heatmap
2. Scan for the max and min values within the heatmap (The minimum value would also need to be considered, since points could potentially have a negative weighting set resulting in raster values < 0)
3. Update the cell values with a value relative to the max/min values
I'm wondering if it would be better/more flexible for this to be done via a step in a processing script. Problem is that heatmaps can't be generated via scripts at the moment - this would require moving the heatmap code from a c++ plugin to core (something which should be done at some time in any case). This is on my (distant) radar, alongside adding additional hotspot types such as Getis Ord Gi*. I'm hoping to get funding or some time of sponsorship to tackle this.
Updated by Jürgen Fischer over 3 years ago
- Subject changed from Heathmap in percentage to Heatmap in percentage
Updated by Matthias Kuhn over 3 years ago
Alternative for moving to core:
We could add the possibility to expose a python API from C++ plugins as well. I could provide some code I have written for globe which does exactly this.
Also available in: Atom