search for: gzero

I've tried and give up. I have a matrix of say 200 columns and 400 rows. For each odd ( or even i suppose if i wanted to )column, I want to know the number of rows in which the value is greater than zero. So, I did sapply(tempMatrix,2,function(x) sum( x > 0 )) this almost works but i don't know how to tell it to only do the odd columns. my guess is , like everything else in R, this

I would like to solve the following function in R: G <- function(k) (2*(1 - k)*(1 + 2*k)^.5)/(1+3*k) I want to be able to find "k" for a given "G" Thanks! Francois Aucoin [[alternative HTML version deleted]]