Try: mymat <- rowMeans(P, dims=2)
Andy > From: Dimitri Joe > > Hi, > > I got 1000 NxN matrices grouped in one array. I want one > matrix in which p_ij is the average of all the 1000 matrices > in the array. Here's what I'm trying to do: > > # P is the NxNx1000 array > > for(i in 1:N) > for(j in 1:N) > for(k in 1: 1000) > mymat[ i, j ] <- mean( P [i , j , k ] ) > > Otherwise, I could have a NxNx1000 vector, and get the N^2 > means of the 1+ (N^2)*(0: 999) elements. I don't know which > is more efficient, but I wouldn't know how to carry this last > solution out anyway. Any ideas on how to do this efficiently? > > Thanks, > > Dimitri > [[alternative HTML version deleted]] > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > > > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
