Thank you for all your replies. Borrowing an alternative solution kindly provided by Mark Leeds, I am using a conditional statement to pass non-zero values to a holding matrix that has cells initially set to NA. The code is as follows:
##Code Start mat_zeroless<-matrix(NA,5000,2000) #generating holding matrix for (j in 1:5000) { for (k in 1:2000) { if(mat[j,k]!=0) {mat_zeroless[j,k]<-mat[j,k]} } } ##Code End Problems arise when the algorithm encounters NAs. Numbers are passed to the holding matrix, and zeros not, but when an NA is encountered, the following error is generated: Error in if mat[j,k] !=0 { :missing value where TRUE/FALSE needed I'm not sure how to resolve this. Thanks, rcoder Henrik Bengtsson (max 7Mb) wrote: > > FYI, > > there is an isZero() in the R.utils package that allows you to specify > the precision. It looks like this: > > isZero <- function (x, neps=1, eps=.Machine$double.eps, ...) { > (abs(x) < neps*eps); > } > > /Henrik > > On Wed, Aug 13, 2008 at 8:23 AM, Roland Rau <[EMAIL PROTECTED]> > wrote: >> Hi, >> >> since many suggestions are following the form of >> x[x==0] (or similar) >> I would like to ask if this is really recommended? >> What I have learned (the hard way) is that one should not test for >> equality >> of floating point numbers (which is the default for R's numeric values, >> right?) since the binary representation of these (decimal) floating point >> numbers is not necessarily exact (with the classic example of decimal >> 0.1). >> Is it okay in this case for the value zero where all binary elements are >> zero? Or does R somehow recognize that it is an integer? >> >> Just some questions out of curiosity. >> >> Thank you, >> Roland >> >> >> rcoder wrote: >>> >>> Hi everyone, >>> >>> I have a matrix that has a combination of zeros and NAs. When I perform >>> certain calculations on the matrix, the zeros generate "Inf" values. Is >>> there a way to either convert the zeros in the matrix to NAs, or only >>> perform the calculations if not zero (i.e. like using something similar >>> to >>> an !all(is.na() construct)? >>> >>> Thanks, >>> >>> rcoder >> >> ______________________________________________ >> 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. >> > > ______________________________________________ > 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. > > -- View this message in context: http://www.nabble.com/ignoring-zeros-or-converting-to-NA-tp18948979p18970797.html 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.