How to speed up int2bin conversion?
You might be interested in package "bit".
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Sent from my phone. Please excuse my brevity.
"Jonas J?germeyr" <jonasjae at pik-potsdam.de> wrote:
Dear R-help members,
I'm processing a large amount of MODIS data where quality assessment
information is stored as an integer value for each pixel. I have to
converted this number to an 8 digit binary flag to get access to the
stored quality code (e.g. in2bin(165,8) = 1 0 1 0 0 1 0 1).
Unfortunately, I did not manage to find a package providing a fast
function to do so. I need to run this on millions of pixels and thus
wrote the following function.
int2bin <- function(x,ndigits){
base <- array(NA, dim=c(length(x), ndigits))
for(q in 1:ndigits){
base[, ndigits-q+1] <- (x %% 2)
x <- (x %/% 2)
}
bin<- apply(base,1,paste,collapse="")
return(bin)
}
Since it is still slow, I have to find a way to express this more
elegantly. I'd really appreciate any help.
Thanking you, with best regards
Jonas J?germeyr
Potsdam Institute for Climate Impact Research
Research Domain II
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