Interchange 1 and 2 (see ?apply: Andy was answering the subject line, not that in the body).
However, Max asked also for column medians of a data frame, for which use sapply(DF, median) I didn't understand the question, and it seems I was not alone :) On Fri, 20 Jan 2006, Philippe Grosjean wrote: > Note that there is a confusion here: 1st dimension is row, 2nd dimension > is column for matrix & data.frame. And the dim arg to apply is the one you want the answer to have. A <- matrix(runif(6), 2, 3) apply(A, 1, median) # row medians apply(A, 2, median) # col medians > So, if the question is about "rowMedian", you have: > > > rowMedian <- function(x, na.rm = FALSE) > > apply(x, 2, median, na.rm = na.rm) > > Now, you ask for the "median for specified columns", which should be as > Andy proposes you, or, if you really want a colMedian function: > > > colMedian <- function(x, na.rm = FALSE) > > apply(x, 1, median, na.rm = na.rm) > > Best, > > Philippe Grosjean > > Liaw, Andy wrote: >> apply(x, 1, median) should do it. If not, you need to explain why. >> >> Andy >> >> -----Original Message----- >> From: Max Kauer >> Sent: Friday, January 20, 2006 10:24 AM >> To: [email protected] >> Subject: [R] function for rowMedian? >> >> >> Hi >> is anybody aware of a function to calculate a the median for specified >> columns in a dataframe or matrix - so analogous to rowMeans? >> Thanks >> Max -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [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
