HI, Try this: m[m==0]<-NA apply(m,1,mean,na.rm=T) #[1] 2.5 NaN 1.0 A.K.
----- Original Message ----- From: Yingwei Lee <[email protected]> To: [email protected] Cc: Sent: Friday, August 17, 2012 11:28 PM Subject: [R] Row means of matrix. Hi all, I'm just having trouble getting row means of a matrix which contain zero. For example. m=matrix(c(1:4, c(0, 0, 0, 0), c(1, 0, 1, 1)), nc=4, byrow=TRUE) I want to be able to calculate means for non-zero elements for each row. ## what i have is this apply((m[apply(m != 0, MARGIN=1, any),]), 1, mean) ## which returns [1] 2.50 0.75 ### what i want to get returned is this [1] 2.50 *1 *meaning that the last row calculated the mean ignoring the zero. Anyone got any ideas? [[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 and provide commented, minimal, self-contained, reproducible code. ______________________________________________ [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 and provide commented, minimal, self-contained, reproducible code.
