#832 closed defect (fixed)
Raster cell coount returns incorrect value
| Reported by: | timlinux | Owned by: | timlinux |
|---|---|---|---|
| Priority: | major: does not work as expected | Milestone: | |
| Component: | Build/Install | Version: | Trunk |
| Keywords: | raster | Cc: | |
| Must Fix for Release: | Yes | Platform: | All |
| Platform Version: | Awaiting user input: | no |
Description
Original report submitted by Enrico Chiaradia:
Currently I use the "ganymede" release and I have to submit this problem: when I load an ASCII raster grid (see attached file), I find in metadata file properties many informations like mean value and the number of cells with value different from no-data value. At the moment, these informations are not correct. In the attached file, you can see that the total number of cell with a different value from nodata are 100; Qgis reports only 99 and this problem affects also average value. I hope that this information is useful and also I wish to actively contribute to the project in the future. Kindly Regards
Enrico Chiaradia
University of Milan, Italy.
NCOLS 10 NROWS 10 XLLCENTER 1535380.000000 YLLCENTER 5083260.000000 DX 10 DY 10 NODATA_VALUE -9999 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 PROJECTION NOTES
I found the problem and have committed a fix for it as r7650. The fixed version will be in the release of QGIS 0.9.1 next month and is availably imediately from SVN trunk if you compile from source. I also add a regression test to catch this bug agan with our unit tests if it ever comes back some how.
Raster metadata for the layer now returns:
Propriedade Valor Banda Undefined No da Banda 1 Val Min 0.0000000000 Val Máx 9.0000000000 Intervalo 9.0000000000 Média 4.5000000000 Soma das raízes 824.9521674896 Desvio Padrão 2.8866676595 Soma de todas as células 450.0000000000 Número de Células 100
If you would like to make more bug reports please let me know your preferred user name and password and I will create an account on our qgis trac site for you. We prefer bugs reported via the bug tracker since its less likely they will be overlooked in our overflowing mail boxes. You are always welcome to email me citing a particlar bug in the queue if you have something particularly urgent that needs attention (assuming I am ablt to help with it).
Best regards
Tim