[R] suggested method to transform list to a matrix

I have data in the following list format: USER,VARIABLE,COUNT user1, var1, 3 user1, var2, 4 user2, var1, 7 userN, var12, 5 And would like to have it format as a matrix: var1var2var12 user1 3 4 user2 7 userN

Re: [R] suggested method to transform list to a matrix

Use matrix subsetting like this: x - matrix(1:9,3) rownames(x) - letters[1:3] colnames(x) - LETTERS[1:3] print(x) usrs - c(a,b,a) vars - c(C,C,A) counts - c(10,11,12) x[cbind(usrs, vars)] - counts print(x) Hope this helps, Michael On Thu, Apr 19, 2012 at 1:48 PM, Tim Stutt

Re: [R] suggested method to transform list to a matrix

On Apr 19, 2012, at 1:48 PM, Tim Stutt wrote: I have data in the following list format: USER,VARIABLE,COUNT user1, var1, 3 user1, var2, 4 user2, var1, 7 userN, var12, 5 And would like to have it format as a matrix: var1var2var12 user1 3