yes you're right; it was my mistake. Best, Dimitris
---- Dimitris Rizopoulos Ph.D. Student Biostatistical Centre School of Public Health Catholic University of Leuven Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/(0)16/336899 Fax: +32/(0)16/337015 Web: http://med.kuleuven.be/biostat/ http://www.student.kuleuven.be/~m0390867/dimitris.htm ----- Original Message ----- From: "Rolf Turner" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Cc: <r-help@stat.math.ethz.ch> Sent: Monday, May 29, 2006 1:55 PM Subject: Re: [R] newbie question: ROW average > Dimitris Rizopoulos wrote: > >> look at ?rowMeans; you can also use "apply(mat, 1, mean)" but >> rowMeans() is better. > > By my reading of the question, this is not what > Ezhil wants. He said: > > ``I have a 992 x 74 matrix. I would like to form a new matrix > by averaging each 4 rows from the original one.'' > > I.e. he wants (I think) the first row of the new matrix > to be the mean of the first 4 rows of the old one, the > second row of the new matrix to be the mean of rows 5 > through 8 of the old one, and so on. > > One way this could be done is via > > > m.new <- t(apply(array(t(m.old),dim=c(74,4,992/4)),c(1,3),mean)) > > cheers, > > Rolf Turner > [EMAIL PROTECTED] > Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
