On Fri, 15 Oct 2004, Sundar Dorai-Raj wrote: > Luis Rideau Cruz wrote: > > > I have a martix with missing values( in which I want the sample size by > > column) > > When I : > > > > apply(matrix,2,length) > > > > I get the length of the vector regardless of missing values. > > I can't pass an argument to length in apply. > > > > Alternatively I could > > > > ifelse ( is.na ( matrix [, "columns in matrix " ] ) , 0 , 1) > > > > Is there any easier way? > > > > I think you almost have it: > > colSums(ifelse(is.na(x), 0, 1)) > > will return the number of non-NA elements in each column of x.
colSums(!is.na(x)) is the same, and more obvious, I think. Remember logical values are coerced to 0/1 in an arithmetical context. -- 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
