!= nodata) * rasterA + (rasterB != nodata) * (rasterA + rasterB)". Query it, I cannot set it to 0 which would solve all my problems.Ĥ) I would like to express something like "(rasterB = nodata AND rasterA Why is "rasterA + nodata = nodata"? I just want valuesįrom rasterB to be added to values of rasterA AND keeping rasterAģ) How can I query the "nodata" value of a band? Without being able to Is that correct?Ģ) I extended rasterB to have the same extent as rasterA by filling the In this case all cells outside theĮxtent of rasterB get assigned "nodata" which is the default When I add these rasters (rasterA + rasterB) and set the outputĮxtent to the same as of rasterA, my result is only defined at the Rather I have someġ) I have two raster with different extents. Iĭon't want to complain about the unintuitive syntax. Super-simple overlay calculations and I'm ending up in rage and fury. In QGIS 2.6.1 I spent the whole day on the raster calculator for some Of the rasters (in vectors) and then use the vectors to raster operation Use the AND function to combine areas and find where raster A and B RasterA/rasterA should give you a mask with 1 where there is data and That explains what is going on in point 1 and 2.Īs for point 4, you can probably do it with a mask. If you multiply a value by a null value, you will get a null value in Save the file in ASCII grid format, you will have no more null values. ItĬan be change with gdal-warp or gdal-translate.
Yes that is a standard null data for float 16 or float 32 files. In this case all cells outside the extent of rasterB get assigned I am not a raster math genius but I will give this a shot.ġ)".
(hoping to reverse engineer this process) Sorting this out, but do not have a ready answer for what must be aįairly common user context. I have learned a lot about QGIS in the process of Have extended your example raster B to the extent of raster A (whichįills in the new area of raster B with nodata values), you can use theĬon(IsNull) statement to transform to null values to zero for use in Null values with some real number for calculations. Replace a given value with a null value for symbology, versus replacing
#ARCMAP RASTER CALCULATOR NODATA HOW TO#
The issues is most of the posts related to this are addressing how to Provided to no success (and many more leads - see below). I tried many of the suggestions in the links Nicolas Ĭoincidentally, I also spent the better part of a whole day trying toįigure out how to do the exact same thing yesterday with two float32 Subject: Re: Raster calculator: different,extents and nodata
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