Hi Erik, IIUC, you would need something like the following:
r.mapcalc expression="bla = if(elev <= 25, 0.0, elev)" or r.mapcalc expression="bla = if(elev <= 25, null(), elev)" HTH, Vero El mié, 10 feb 2021 a las 8:47, Erik Victor Lundstrøm (< [email protected]>) escribió: > Hi everyone, > > I've done some google searches related to my problem. Granted, by no > means exhaustive, but unsuccessful nonetheless. > Thus, I hereby by contribute with my first post in the email group > hoping to find some help. > > I work in coastal Norway, and I'd like to produce different rasters > based on estimates for when the sea-level was either higher, or lower, > than today. > When I started doing this years ago, it was simply enough for me to use > the raster calculator and then produce binary maps using the "<=" or > ">=" expression as I only wanted to visualise the difference. > However, today I'd like to continue to work with the rasters where the > values on the other side of the threshold that I assign remain intact > but > I find it way too tedious having to 1) produce a binary map, 2) convert > the cells denoting the sea-level change into vector polygons, and then > 3) clipping the old raster into a new one. > > I'll try and use an example for what I'd like to try and achieve > instead. > > Let's say I have an elevation raster with values ranging from -0.001 to > 1500m. Now, if I'd be interested in producing a raster where anything > below 25m is submerged, then the method that I alluded > to above would produce the following raster = 0 & 1 > > What I'm interested in doing now instead, is to find some method where I > still reset anything below 25m as "0", but where I still have all the > remaining values intact. > > I'm thinking that there should be a way, either through the raster > calculator or the reclassify tool, where I could simply reset anything > above or below a certain threshold as either "0", or perhaps even "no > data" but at the same time keep all the other elevation values of the > raster intact. > > This message should hopefully be enough to indicate that I have > relatively poor experience with both the reclassify or mapcalc-tool and > thus any > brief guide on how I could solve my problem would be greatly > appreciated! > > If anything is unclear just let me know and I can try to reformulate. > > Best, > Victor > _______________________________________________ > grass-user mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/grass-user >
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