Re: [R] matrix help (first occurrence of variable in column)

On Wed, May 18, 2011 at 9:49 PM, jim holtman jholt...@gmail.com wrote: Is this what you were after: mdat - matrix(c(1,0,1,1,1,0), nrow = 2, ncol=3, byrow=TRUE, +               dimnames = list(c(T1, T2), +                               c(sp.1, sp.2, sp.3))) mdat   sp.1 sp.2 sp.3 T1    1    

Re: [R] matrix help (first occurrence of variable in column)

Is this what you are looking for: mdat3 sp.1 sp.2 sp.3 sp.4 sp.5 T110010 T210010 T311100 T410111 # create a matrix of when species first appeared first - apply(mdat3, 2, function(x) (cumsum(x == 1) 0) + 0L) #

[R] matrix help (first occurrence of variable in column)

Dear R help, Apologies for the less than informative subject line. I will do my best to describe my problem. Consider the following matrix: mdat - matrix(c(1,0,1,1,1,0), nrow = 2, ncol=3, byrow=TRUE, dimnames = list(c(T1, T2), c(sp.1, sp.2, sp.3)))

Re: [R] matrix help (first occurrence of variable in column)

Is this what you were after: mdat - matrix(c(1,0,1,1,1,0), nrow = 2, ncol=3, byrow=TRUE, + dimnames = list(c(T1, T2), + c(sp.1, sp.2, sp.3))) mdat sp.1 sp.2 sp.3 T1101 T2110 # do 'rle' on each column and see if it is