search for: multiplcation

Friends I'm not seeing why the following occurs: > T1 <- (A1 - A2) %*% D > T2 <- (A1 %*% D) - (A2 %*% D) > identical(T1, T2) [1] FALSE Harold > dput(A1) new("dsCMatrix" , i = c(0L, 1L, 2L, 3L, 0L, 1L, 4L, 2L, 3L, 5L) , p = c(0L, 1L, 2L, 3L, 4L, 7L, 10L) , Dim = c(6L, 6L) , Dimnames = list(NULL, NULL) , x = c(5, 5, 5, 5, 5, 5, 10, 5, 5, 10)

...1 2 3 4 1 1 0 0 0 2 3 4 It is important for the zero's to retain their position as this matrix will subsequently be used in some matrix multiplication and hence, must be of dimension 4 by 4 so that is it conformable for multiplcation with another matrix. In looking at the structure of the object resulting from prop.table I see NaNs, and so I can do this > rr <- TP[[18]] > rr[is.na(rr)] <- 0 > rr level2 level1 1 2 3 4 1 79 0 0 0 2 0 0 0 0 3 0 0 0 0 4 0 0 0 0 This is...

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> -- 1.7.10.4