[R] apply on rows and columns?

I have the following scenario: m - matrix(1:4, ncol=2) m [,1] [,2] [1,]13 [2,]24 apply(m, 2, sum) [1] 3 7 apply(m, 1, sum) [1] 4 6 So I can apply to rows *or* columns. According to the documentation (?apply) MARGIN a vector giving the subscripts which the function

Re: [R] apply on rows and columns?

It's the same as what you began with -- and that's because you broke it down by columns and rows and took the sum of everything that resulted. I.e., sum(m[1,1]) sum(m[2,1]) sum(m[1,2]) sum(m[2,2]) and put them back together. Michael On Wed, Nov 16, 2011 at 3:13 PM, rkevinbur...@charter.net

Re: [R] apply on rows and columns?

Hi, On Wed, Nov 16, 2011 at 3:13 PM, rkevinbur...@charter.net wrote: I have the following scenario: m - matrix(1:4, ncol=2) m      [,1] [,2] [1,]    1    3 [2,]    2    4 apply(m, 2, sum) [1] 3 7 apply(m, 1, sum) [1] 4 6 So I can apply to rows *or* columns. According to the

Re: [R] apply on rows and columns?

To expand on what Sarah and Michael said: if you have a 3d array: x-array(1:4,c(2,2,4)) x , , 1 [,1] [,2] [1,]13 [2,]24 , , 2 [,1] [,2] [1,]13 [2,]24 , , 3 [,1] [,2] [1,]13 [2,]24 , , 4 [,1] [,2] [1,]13 [2,]