Hi, I deal with 3D array say: , , 1
[,1] [,2] [,3] [,4] [,5] [1,] 1 4 7 10 13 [2,] 2 5 8 11 14 [3,] 3 6 9 12 15 , , 2 [,1] [,2] [,3] [,4] [,5] [1,] 16 19 22 25 28 [2,] 17 20 23 26 29 [3,] 18 21 24 27 30 , , 3 [,1] [,2] [,3] [,4] [,5] [1,] 31 34 37 40 43 [2,] 32 35 38 41 44 [3,] 33 36 39 42 45 I want to calculate means in the cells with respect to dimention 3rd so for example (1+16+31)/3 or (15+30+45)/3 AND avoid taking zeros into account. I did it with a loop but I guess there is the other more straightforward method. will be very grateful for help... best, rob -- View this message in context: http://www.nabble.com/3D-array-tf4940356.html#a14142187 Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@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.