Bug report #3167
calculation of ruggedness
| Status: | Closed | ||
|---|---|---|---|
| Priority: | Low | ||
| Assignee: |  nobody - | ||
| Category: | Rasters | ||
| Affected QGIS version: | Regression?: | No | |
| Operating System: | All | Easy fix?: | No |
| Pull Request or Patch supplied: | Resolution: | wontfix | |
| Crashes QGIS or corrupts data: | Copied to github as #: | 13227 |
Description
In browsing the code for ruggedness I found something odd.
The formula is missing division by n prior to the execution of sqrt if it is supposed to be standard deviation from the centre pixel.
Since there is no documentation on the formula that was intended, I don't know if this is intentional or a bug.
History
#1
Updated by Marco Hugentobler over 13 years ago
- Resolution set to wontfix
- Status changed from Open to Closed
Ruggedness index is calculated according to Riley et al. 1999 (see corrected formula in http://www.fw.msu.edu/~rileysh2/Terrain%20Ruggedness%20Index.pdf). There is no division by the number of pixels, only the root of the squares is taken.