One additional thing to note is that %>% will have different precedence than > (something that was pointed out to me based on %<% that is in the TeachingDemos package).
-- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.s...@imail.org 801.408.8111 > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of Timothy Bates > Sent: Tuesday, September 13, 2011 10:42 AM > To: R list > Subject: [R] x %>% y as an alternative to which( x > y) > > Dear R cognoscenti, > > While having NA as a native type is nifty, it is annoying when making > binary choices. > > Question: Is there anything bad about writing comparison functions that > behavior like %in% (which I love) and ignore NAs? > > "%>%" <- function(table, x) { > return(which(table > x)) > } > > "%<%" <- function(table, x) { > return(which(table < x)) > } > > test <- c(NA, 1:4,NA,5) > test %>% 2 > # [1] 3 4 6 > test %<% 2 > # [1] 1 > > Why do I want to do this? > > Because in coding, I often end up with big chunks looking like this: > > ((mydataframeName$myvariableName > 2 & > !is.na(mydataframeName$myvariableName)) & > (mydataframeName$myotherVariableName == "male" & > !is.na(mydataframeName$myotherVariableName))) > > Which is much less readable/maintainable/editable than > > mydataframeName$myvariableName > 2 & > mydataframeName$myotherVariableName == "male" > > But ">" returns anything involving an NA, so it breaks selection > statements (which can't contain NA) and leaves lines in data that are > wished to be excluded > > If this does not have nasty side-effects, it would be a great addition > to GTD* in R > > If anyone knows a short cut to code the effect I wish, love to hear it. > > Cheers, > tim > > * GTD = Getting Things Done > > > -- > The University of Edinburgh is a charitable body, registered in > Scotland, with registration number SC005336. > > ______________________________________________ > 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.
