how to calculate means of matrix elements
In that case use a modification of Jim's solution: a <- array(cbind(mat1, mat2, mat3), c(3, 3, 3)) apply(a, 1:2, mean, na.rm = TRUE)
On Tue, May 19, 2009 at 8:49 AM, dxc13 <dxc13 at health.state.ny.us> wrote:
Easy enough. ?What if some of the matrix elements contained missing values? Then how could you still calculate the means? ?Example code below: mat1 <- matrix(c(1,2,3,4,5,NA,7,8,9),3,3) mat2 <- matrix(c(NA,6,1,9,0,5,8,2,7),3,3) mat3 <- matrix(c(5,9,1,8,NA,3,7,2,4),3,3) Gabor Grothendieck wrote:
Try this: (mat1 + mat2 + mat3) / 3 On Mon, May 18, 2009 at 8:40 PM, dxc13 <dxc13 at health.state.ny.us> wrote:
useR's, I have several matrices of size 4x4 that I want to calculate means of their respective positions with. ?For example, consider I have 3 matrices given by the code: mat1 <- matrix(sample(1:20,16,replace=T),4,4) mat2 <- matrix(sample(-5:15,16,replace=T),4,4) mat3 <- matrix(sample(5:25,16,replace=T),4,4) The result I want is one matrix of size 4x4 in which position [1,1] is the mean of position [1,1] of the given three matrices. ?The same goes for all other positions of the matrix. ?If these three matrices are given in separate text files, how can I write code that will get this result I need? Thanks in advance, dxc13 -- View this message in context: http://www.nabble.com/how-to-calculate-means-of-matrix-elements-tp23607694p23607694.html Sent from the R help mailing list archive at Nabble.com.
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
-- View this message in context: http://www.nabble.com/how-to-calculate-means-of-matrix-elements-tp23607694p23615755.html Sent from the R help mailing list archive at Nabble.com.
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.