r <- raster()
r <- setValues(r, 1:ncell(r))
minValue(r)
maxValue(r)
r <- setValues(r, round(100 * runif(ncell(r)) + 0.5))
minValue(r)
maxValue(r)
r <- raster(system.file("external/test.grd", package="raster"))
# this raster is from an 'external' format, so min and maxValue are not known
minValue(r)
maxValue(r)
r1 <- setMinMax(r)
# now they are known:
minValue(r1)
maxValue(r1)
r2 <- readAll(r)
# now they are known too:
minValue(r2)
maxValue(r2)
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