Bug report #11350
Raster Calculator not giving the correct raster from a slope percentage raster
| Status: | Closed | ||
|---|---|---|---|
| Priority: | High | ||
| Assignee: | - | ||
| Category: | Raster Calculator | ||
| Affected QGIS version: | 2.4.0 | Regression?: | No |
| Operating System: | Easy fix?: | No | |
| Pull Request or Patch supplied: | No | Resolution: | invalid |
| Crashes QGIS or corrupts data: | No | Copied to github as #: | 19641 |
Description
i have a srtm_62_11 downloaded from the internet with WGS84 projection. I tried to derived slope raster from the srtm (DEM) as percentage instead of degrees and a z-factor of 113200 to convert degrees in meters (please correct me in this factor) using the Raster>>Analysis>>DEM. i have successfully made the slope raster with 0.607858 and 62.4067 as min and max values (i believe its in percentage. However when i try to use the raster calculator to derived a new raster with slope of less than or equal to 8 ("slope%@1" <= 8 using this expression), i didn't get the correct values. i only get a 0 and .999 as min and max values for the new raster.
Am i doing the right procedure or an error in the process? I'll appreciate your help.thanks
History
#1
Updated by Nicolas Cadieux almost 10 years ago
I think you are getting 0 and 1. 0 for cells that don't meet the requirements and 1 where the cells do. You then need to multiply that by your slope layer so that the 1 get multiplied by the slope values and the 0 stay zeros...
#2
Updated by Prime Enrique Rendon almost 10 years ago
how can i multiple the said values to my slope? but i'm still looking for ways to multiply it. thanks for the reply.
#3
Updated by Nyall Dawson over 9 years ago
- Resolution set to invalid
- Status changed from Open to Closed
An expression like:
("slope%@1" <= 8 ) * "slope%@1"
will work