getting mean values for each raster in a stack
Dear Pebesma
No I din't, thanks. Probably I have not read enough.
extract package:raster
fun: function to summarize the values (e.g. ?mean?). The function
should take a single numeric vector as argument and return a
single value (e.g. mean, min or max), and accept a ?na.rm?
argument ... ??
Thanks again.
A.O.
2016-05-16 18:01 GMT-03:00 Edzer Pebesma <edzer.pebesma at uni-muenster.de>:
Did you try: extract(stack, polygon, mean) ? On 16/05/16 22:50, Antonio Silva wrote:
Hi, After many trials and some reading I got what I need apply(vals[[1]],2,mean) Anyway I would welcome comments to improve this solution. Best regards Antonio Olinto 2016-05-16 15:32 GMT-03:00 Antonio Silva <aolinto.lst at gmail.com>:
Dear R users
I have a raster stack and a polygon.
I want the mean value inside this polygon for each raster in the stack.
I'm doing the following:
vals <- extract(stack,polygon)
colMeans(r.vals[[1]]) # only for mean values
# or
for (i in 1:nlayers(stack)) {print(mean(vals[[1]][,i]))} # mean or other
parameter
I also tried to use lapply, but I got only the overall mean with
lapply(vals, FUN=mean)
I wonder if there is a way to get the mean (and other parameters) for
each
layer using lapply function. Thanks in advance. Antonio Olinto
-- Edzer Pebesma Institute for Geoinformatics (ifgi), University of M?nster Heisenbergstra?e 2, 48149 M?nster, Germany; +49 251 83 33081 Journal of Statistical Software: http://www.jstatsoft.org/ Computers & Geosciences: http://elsevier.com/locate/cageo/ Spatial Statistics Society http://www.spatialstatistics.info
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