Omit inf from row sum in R

Question

So I am trying to sum the rows of a matrix, and there are inf\'s within it. How do I sum the row, omitting the inf\'s?

Answer 1

This is a "non-apply" and non-destructive approach:

rowSums( matrix(match(A, A[is.finite(A)]), nrow(A)), na.rm=TRUE)
[1] 2 4

Although it is reasonably efficient, it is not as fast as Johsua's multiplication method.