Bug report #14678
Updated by Nyall Dawson about 5 years ago
I'm working in QGIS 2.14.1 with a DEM ranging from 200 feet to 1600 feet elevation called "dem_3m_Zft1b" (geotiff, 16822 X 33349 cells, No-data =-9999)
If I enter "dem_3m_Zft1b" > 0
in the raster calculator I get a result that has a value of 0 everywhere in the raster extent. The calculator does not seem to recognize the existence of any values or of the no-data flag.
With a subset/portion of the DEM called "atest9b@1" (4489 X 6175 cells, No-data=-9999), If I enter "atest9b@1" > 0 in the raster calculator I get a result that has a value of 1 where there was data and a value of no-data where there was no-day. Everything seems OK when using the subset.
The larger DEM "dem_3m_Zft1b" seems OK in other ways, e.g. the "Identify" tool finds valid values for Band1, but the raster calculator doesn't seem to recognize the data in it.
I tried the same operation on the large DEM in the Processing Toolbox, SAGA, Raster Calculator with the syntax: g1 > 0 and I get the correct results, i.e. 1 where there is data and no-data where there isn't.
If I enter "dem_3m_Zft1b" > 0
in the raster calculator I get a result that has a value of 0 everywhere in the raster extent. The calculator does not seem to recognize the existence of any values or of the no-data flag.
With a subset/portion of the DEM called "atest9b@1" (4489 X 6175 cells, No-data=-9999), If I enter "atest9b@1" > 0 in the raster calculator I get a result that has a value of 1 where there was data and a value of no-data where there was no-day. Everything seems OK when using the subset.
The larger DEM "dem_3m_Zft1b" seems OK in other ways, e.g. the "Identify" tool finds valid values for Band1, but the raster calculator doesn't seem to recognize the data in it.
I tried the same operation on the large DEM in the Processing Toolbox, SAGA, Raster Calculator with the syntax: g1 > 0 and I get the correct results, i.e. 1 where there is data and no-data where there isn't.