Hi, 2017-04-06 11:09 GMT+02:00 RichardCooper <[email protected]>: > I have a time series of rainfall data, and for each year I want to calculate > the five-day period with maximum rainfall. So I would need to calculate the > sum of day1 to day5, then day2 to day6, then day3 to day7 etc for the whole > year, and then output the maximum grid cell 5-day values for each year into > a single raster.
What you need is a temporal moving window with the size of 5 days to compute for each day the 5 day aggregate of the future. You can convert your time series into a voxel dataset (3d raster) and use r3.mapcalc with the neighbor index operator map[x][y][z] (if i remember correctly): agg_map3d = map3d[0][0][0] + map3d[0][0][1] + ... map3d[0][0][4] Or you use t.rast.algebra [1] and the temporal neighbor operator strds[t]: agg_strds = prec_strds[0] + prec_strds[1] + ... prec_strds[4] Best regards Soeren [1] https://grass.osgeo.org/grass73/manuals/t.rast.algebra.html > > To do this in t.rast.accumulate, I can see how to set a temporal cycle of 1 > year (cycle= "12 months"), but not sure how to specify such a rolling sum > calculation of 5 days as described above. The default method is the 'mean' > as indicated in r.series.accumulation? I'm not too sure how the accumulation > is applied in the module. > > Best regards, > Richard > > > > -- > View this message in context: > http://osgeo-org.1560.x6.nabble.com/Temporal-framework-calculating-annual-5-day-extremes-tp5316014p5316076.html > Sent from the Grass - Users mailing list archive at Nabble.com. > _______________________________________________ > grass-user mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/grass-user _______________________________________________ grass-user mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/grass-user
