Hi I have two raster layers
,---- | dc: CELL, 1, ..., 7, NULL | ageClass: CELL, 1,2,3,NULL `---- And I want to create a third one, depending on the value in a lookup table. dc corresponds to the row, ageClass to the column, The lookup table looks as follow: ,---- | seedling young adult | dc1 425000 87500 37500 | dc2 270000 55000 23500 | dc3 127500 26000 11250 | dc4 32500 7100 3200 | dc5 5550 1220 500 | dc6 605 132 55 | dc7 56 12 6 `---- Now I want to have something like (using r.mapcalc as an example) ,---- | r.mapcalc expression = "result = lookupTable[col=ageClass, row=dc]" `---- and e.g. for one cell ,---- | ageClass = 3 | dc = 5 | ==> | result = 500 `---- I haven't found anything like this in GRASS. I could use MASKS and then r.reclass(), or generate dynamically a complex if() construct, but both options sound a little bit awkward to me. I am scripting GRASS from R, so there is always the option of doing it in R, but there is the issue of reading the data into R and writing it back to GRASS, which takes time. As I am doing this in a simulation which runs several times, this is not an unimportant issue. Is there better way of achieving this? Thanks, Rainer -- Rainer M. Krug Centre of Excellence for Invasion Biology Stellenbosch University South Africa Tel : +33 - (0)9 53 10 27 44 Cell: +33 - (0)6 85 62 59 98 Fax : +33 - (0)9 58 10 27 44 Fax (D): +49 - (0)3 21 21 25 22 44 email: [email protected] Skype: RMkrug
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