Hi all,
(if me email goes out as html, than my email client don't do as told, and I
apologies already.)
We need to downscale climate data and therefore first need to expand the
climate from 0.5deg to the higher resolution 10min, before we can add high
resolution deviations. We basically need to have the original data at each
gridcell replicated into 3x3 gridcells.
A simple for loop can do this, but I could need a faster procedure. Anybody
know a faster way? Is there package than can do what we need already?
I tried matrix with rep, but I am missing some magic there, since it doesn't do
what we need.
replicate might be promising, but then still need to rearrange the output into
the column and row format we need.
A simple example:
mm=matrix(1:15,nrow=3,byrow = T)
xmm=matrix(NA,nrow=nrow(mm)*3,ncol=ncol(mm)*3)
for(icol in 1:ncol(mm)) {
for(irow in 1:nrow(mm)) {
xicol=(icol-1)*3 +c(1:3)
xirow=(irow-1)*3 +c(1:3)
xmm[xirow,xicol]=mm[irow,icol]
}
}
mm
> > mm
> [,1] [,2] [,3] [,4] [,5]
> [1,] 1 2 3 4 5
> [2,] 6 7 8 9 10
> [3,] 11 12 13 14 15
>
xmm
> > xmm
> [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13]
> [,14] [,15]
> [1,] 1 1 1 2 2 2 3 3 3 4 4 4 5
> 5 5
> [2,] 1 1 1 2 2 2 3 3 3 4 4 4 5
> 5 5
> [3,] 1 1 1 2 2 2 3 3 3 4 4 4 5
> 5 5
> [4,] 6 6 6 7 7 7 8 8 8 9 9 9 10
> 10 10
> [5,] 6 6 6 7 7 7 8 8 8 9 9 9 10
> 10 10
> [6,] 6 6 6 7 7 7 8 8 8 9 9 9 10
> 10 10
> [7,] 11 11 11 12 12 12 13 13 13 14 14 14 15
> 15 15
> [8,] 11 11 11 12 12 12 13 13 13 14 14 14 15
> 15 15
> [9,] 11 11 11 12 12 12 13 13 13 14 14 14 15
> 15 15
I tried various rep with matrix, but don't get the right result.
xmm2=matrix(rep(rep(mm,each=3),times=3),nrow=nrow(mm)*3,ncol=ncol(mm)*3,byrow =
F)
> identical(xmm,xmm2)
[1] FALSE
rr=replicate(3,rep(t(mm),each=3))
rr
> > rr
> [,1] [,2] [,3]
> [1,] 1 1 1
> [2,] 1 1 1
> [3,] 1 1 1
> [4,] 2 2 2
> [5,] 2 2 2
> [6,] 2 2 2
> [7,] 3 3 3
> ...
identical(xmm,matrix(rr,ncol=15,nrow=9,byrow=T))
> > identical(xmm,matrix(rr,ncol=15,nrow=9,byrow=T))
> [1] FALSE
Many thanks for any advice.
cheers
Peter
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