This is probably a map algebra problem. I have a 2D map with values ranging
1.0 spread all over it. The algorithm that produces them is an application of the fractional Brownian motion. The map measures
101x101 pixels or cells.
My problem: I want to find in the map the regions (or islands) which values exceed a given threshold, e.g.
0.3 (we can call them the hotspots). I then want to calculate the number of pixels or cells that fall within the boundaries of that island. Given that there might be more than one island, I could end up with:
- Situation 1: 1 island with, say,
1000pixels or cells;
- Situation 2: 2 islands with
500pixels or cells each;
- Additional combinations.
Since I must be able to distinguish between the various situations, I was thinking of somehow weighing the total number of cells with respect to the number of islands. How could I do this, other than considering the average number of cells (which I see as a trivial solution)?
I am asking this since if I were to evaluate the impact of those hotspots on a system that is embedded in the map, there might be huge differences between having one big hotspot located in the center of the map and having multiple, although smaller, hotspots scattered all over the place.
Below is a visual example of what I mean by islands or regions.