The question was whether you could do this 'in a single line' and the word 'elegant' was in the subject line. Those two things don't always go together.
You can put semicolons between the statements so they all can go on one line, but that isn't very elegant. You could collapse the three assignments into one, as in third <- e[,23][!is.na(e[,23])][e[,23][!is.na(e[,23])] < 30] but that wastes time repeatedly calculating e[,23] and is.na(...) and is hard to read, both of which count against its elegance score. One could use & to go from 3 assignments to 2, as in first <- e[,23] third <- first[!is.na(first) & first < 30] You could write a function that returns TRUE where its logical input vector is TRUE and FALSE where it is NA or FALSE: is.true <- function(x) !is.na(x) & x and use it as first <- e[,23] third <- first[is.true(first < 30)] To my eyes the last is the most elegant way to do things, as the flow of data is very clear. Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com > -----Original Message----- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] On Behalf Of Bert Gunter > Sent: Wednesday, July 06, 2011 8:50 AM > To: Jim Maas > Cc: r-help@r-project.org > Subject: Re: [R] elegant way of removing NA's and selecting > specific values from a data.frame > > ?"&" > > This is basic. Please read "An Intro to R" before posting any more > such questions if you have not already done so. > > -- Bert > > On Wed, Jul 6, 2011 at 8:35 AM, Jim Maas <j.m...@uea.ac.uk> wrote: > > I have a data.frame "e" and would like to extract the 23rd > column, remove > > any NA's and then remove any values >= 30. I can do it in > steps such as > > this but have failed to figure out how to do it in a single > line .... any > > suggestions? > > > > first <- e[,23] > > second <- first[!is.na(first)] > > third <- second[second<=30] > > > > thanks a bunch > > > > J > > > > -- > > Dr. Jim Maas > > University of East Anglia > > > > ______________________________________________ > > 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. > > > > > > -- > "Men by nature long to get on to the ultimate truths, and will often > be impatient with elementary studies or fight shy of them. If it were > possible to reach the ultimate truths without the elementary studies > usually prefixed to them, these would not be preparatory studies but > superfluous diversions." > > -- Maimonides (1135-1204) > > Bert Gunter > Genentech Nonclinical Biostatistics > > ______________________________________________ > 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.
