Hi there,
I'm having some difficulty adding raster layers. I'm trying to create a species richness map and I was thinking of layering them via the calculator. The files I have are individual species distributions (which are just patches of 1 grids), and I have a main raster of the map of the location (which are patches of 0 grids). Now, when I add the layers on raster calculator (irrespective of order), I end up with just the patches of 1 and the larger map just disappears. This would still happen if the values were 1 and 2 respectively, the grid cells for the main map would just disappear anyway.
What I want is to still have those grids with the value 0 so it would be uniform for all the species so I would be able to overlay all of them at once and get a map of the richness. The size of the cells are the same, and they are under the same projection. I just dont know what might be the reason.
Does anyone know why this happens/what I can do about it?
Any help would be greatly appreciated. Thank you.
Siri
Solved! Go to Solution.
p, I suggest using the Cell Statistics tool with SUM option. That would run faster anyway. If you do have NoData issues there is a checkbox to ignore NoData in the SUM.
If there are areas of NoData in any of the grids, NoData will be returned, see the image here
the values are 0. So technically they should still be carried forward but it doesn't.
p, I suggest using the Cell Statistics tool with SUM option. That would run faster anyway. If you do have NoData issues there is a checkbox to ignore NoData in the SUM.
Hi Curtis,
I've tried the cell statistics tool but I'm facing another problem I can't seem to figure out:
This is basically my file, the blue being the Madagascar area (grid size around 590,000) and pink being species distribution.
However when I use the cell stat sum tool: it produces this raster. I dont know where the green square is coming from?
Would you know why this is happening?
thank you
Siri
Nevermind, I realised I didnt need the base raster afterall. So now its worked! Thank you!!