About this:
foo <- function( files = c( "file1", "file2" ), nr = 3, nc = 3 ){
out <- numeric( nr * nc )
for( i in seq_along(files)){
out <- out + scan( files[i] , what = numeric(0), quiet = TRUE )
}
matrix( out, nr = nr, nc = nc, byrow = T )
}
> foo()
[,1] [,2] [,3]
[1,] 5 5 5
[2,] 7 7 7
[3,] 9 9 9
This would have been more fun if you could store them all in memory at
once (which I think you can't) :
> files <- c("file1", "file2" )
> matrices <- lapply( files, scan, what = numeric(0), quiet = TRUE )
> matrix( Reduce( "+", matrices ), nr = 3, nc = 3, byrow = TRUE )
[,1] [,2] [,3]
[1,] 5 5 5
[2,] 7 7 7
[3,] 9 9 9
Romain
On 12/02/2009 05:53 PM, Muhammad Rahiz wrote:
Dear R-users,
I'd like to perform arithmetic functions on 1000 files containing a
2000x2000 matrix. Can anyone advise?
For example,
File1 File2 Output
1 1 1 4 4 4 5 5 5
2 2 2 + 5 5 5 = 7 7 7
3 3 3 6 6 6 9 9 9
Muhammad
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