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 -- Muhammad Rahiz | Doctoral Student in Regional Climate Modeling Climate Research Laboratory, School of Geography & the Environment Oxford University Centre for the Environment South Parks Road, Oxford, OX1 3QY, United Kingdom Tel: +44 (0)1865-285194 Mobile: +44 (0)7854-625974 Email: muhammad.rahiz at ouce.ox.ac.uk
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
>
--
Romain Francois
Professional R Enthusiast
+33(0) 6 28 91 30 30
http://romainfrancois.blog.free.fr
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Ain't it as simple as load them ("read()" or
"read.csv()"), add (+)
these dataframes and thats all? you also can export them again with
"write()".
greets,
Benjamin M?ller
Muhammad Rahiz schrieb:> 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
>