Why does spatial analyst not work properly for me?

Discussion created by miob on Jun 16, 2011
Latest reply on Jun 21, 2011 by miob
I have been fighting with spatial analyst for days now and it is becomming very frustrating. The problem? Nothing does waht it is supposed to do.

For instance, when I use raster calculater and I use:

outgrid = con([ingrid] > 5, 1, 10)

It is supposed to assign the value of 1 to all cells that have a value higher than 5. It does that perfectly. It is ALSO suposed to assign the value of 10 to all other cells. It doesn't. Al other cells turn into NoData and disappear (the extend of the map/raster also changes)

Same thing happens in the toolbox: If I use plus/minus/times (or any other function) and I apply the function to 2 rasters the output is a raster only covering the overlapping parst of teh raster.

So I reclassified. I gave, for instance, the rasters the same extend and set all NoData to 0. But again: If I use the plus or minus toolbox (even with the extend set to the largest raster in environments) the extend changes to only the part where the original (which I even deleted from the drive) overlap and teh extend changes.

I've tried literally hundreds of small variations to this. It simply does not work.

What is going on?!? I am using Arcmap 9.3