Hi, I am wondering if anybody has a simpler solution to calculate the following:> maa b [1,] 1 4 [2,] 2 3 [3,] 3 2 [4,] 4 5> pa[,1] [,2] [,3] [,4] a 1 2 3 4 b 4 3 2 5> diag(ma%*%pa)[1] 17 13 13 41 I only want to calculate the product of the row of the first matrix and the corresponding column of the second matrix (instead of other columns). However, what I did was to multiply these two and then extract the diagonal components. Is there a simpler way to do this in R? (ma and pa may not be the same matrix.) Thanks! ______________________________________________________ Donate to the Hurricane Katrina relief effort.
Try this: rowSums(ma * t(pa)) On 9/13/05, Cunningham Kerry <kerryrekky at yahoo.com> wrote:> Hi, > I am wondering if anybody has a simpler solution to > calculate the > following: > > > ma > a b > [1,] 1 4 > [2,] 2 3 > [3,] 3 2 > [4,] 4 5 > > pa > [,1] [,2] [,3] [,4] > a 1 2 3 4 > b 4 3 2 5 > > diag(ma%*%pa) > [1] 17 13 13 41 > > I only want to calculate the product of the row of the > first matrix and > the corresponding column of the second matrix (instead > of other > columns). However, what I did was to multiply these > two and then extract > the diagonal components. Is there a simpler way to do > this in R? (ma and pa may not be the same matrix.) > > Thanks! > > > > > ______________________________________________________ > > Donate to the Hurricane Katrina relief effort. > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! R-project.org/posting-guide.html >