Here is a way of reading the data into a 'list'. You can convert the list
to any array of the proper dimensions.
> input <- scan('/tempxx.txt.r', what='')
Read 21 items
> input
[1] "SPECIES1" "999001099" "900110109" "011101000" "901100101" "110100019"
[7] "901110019" "SPECIES2" "999000099" "900110119" "011101100" "901010101"
[13] "110000019" "900000019" "SPECIES3" "999001099" "900100109" "011100010"
[19] "901100100" "110100019" "901110019"
> # find the names
> breaks <- grep("[[:alpha:]][[:alnum:]]+", input)
> # determine the sizes
> map <- cbind(breaks, diff(c(breaks, length(input)+1)))
> out <- list()
> # repeat for each data block
> for (i in 1:nrow(map)){
+ .set <- NULL
+ for (j in 1:(map[i, 2] - 1)){
+ .set <- rbind(.set, strsplit(input[map[i, 1] + j], '')[[1]])
+ }
+ out[[input[map[i, 1]]]] <- .set
+ }
> out
$SPECIES1
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9]
[1,] "9" "9" "9" "0" "0" "1" "0" "9" "9"
[2,] "9" "0" "0" "1" "1" "0" "1" "0" "9"
[3,] "0" "1" "1" "1" "0" "1" "0" "0" "0"
[4,] "9" "0" "1" "1" "0" "0" "1" "0" "1"
[5,] "1" "1" "0" "1" "0" "0" "0" "1" "9"
[6,] "9" "0" "1" "1" "1" "0" "0" "1" "9"
$SPECIES2
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9]
[1,] "9" "9" "9" "0" "0" "0" "0" "9" "9"
[2,] "9" "0" "0" "1" "1" "0" "1" "1" "9"
[3,] "0" "1" "1" "1" "0" "1" "1" "0" "0"
[4,] "9" "0" "1" "0" "1" "0" "1" "0" "1"
[5,] "1" "1" "0" "0" "0" "0" "0" "1" "9"
[6,] "9" "0" "0" "0" "0" "0" "0" "1" "9"
$SPECIES3
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9]
[1,] "9" "9" "9" "0" "0" "1" "0" "9" "9"
[2,] "9" "0" "0" "1" "0" "0" "1" "0" "9"
[3,] "0" "1" "1" "1" "0" "0" "0" "1" "0"
[4,] "9" "0" "1" "1" "0" "0" "1" "0" "0"
[5,] "1" "1" "0" "1" "0" "0" "0" "1" "9"
[6,] "9" "0" "1" "1" "1" "0" "0" "1" "9"
>
On 12/22/05, Colin Beale <[EMAIL PROTECTED]> wrote:
>
> Hi,
>
> I'm needing some help finding a function to read a large text file into an
> array in R. The data are essentially presence / absence / na data for many
> species and come as a grid with each species name (after two spaces) at the
> beginning of the matrix defining the map for that species. An excerpt could
> therefore be:
>
> SPECIES1
> 999001099
> 900110109
> 011101000
> 901100101
> 110100019
> 901110019
>
> SPECIES2
> 999000099
> 900110119
> 011101100
> 901010101
> 110000019
> 900000019
>
> SPECIES3
> 999001099
> 900100109
> 011100010
> 901100100
> 110100019
> 901110019
>
> where 9 is actually na, 0 is absence and 1 presence. The final array I
> want to create should have dimensions that are the x and y coordinates and
> the number of species (known in advance). (In this example dim = c(9,6,3)).
> It would be sort of neat if the code could also read the species name into
> the appropriate names attribute, but this is a refinement that I could
> probably do if someone can help me read the data into R and into an array in
> the first place. I'm currently thinking a line by line approach using
> readLines might be the best option, but I've got a very long file - well
> over 100 species, each a matrix of 70 x 100 datapoints. making this option
> rther time consuming, I expect - especially as the next dataset has 1300
> species and a much larger grid...
>
> Any hints would be gratefully recieved.
>
> Colin Beale
> Macaulay Land Use Research Institute
>
> ______________________________________________
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>
--
Jim Holtman
Cincinnati, OH
+1 513 247 0281
What the problem you are trying to solve?
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