Hello,
First, your statement can be re-written as sort(x,partial=p)[p] since n - (n - p) is p. Second, you need to look at ?sort And look at section "Arguments" subsection "partial", that should have the details you're looking for. From what I understand, it guarantees that the indices of "partial" will be sorted correctly, but all others won't, so this saves time for things like "median". I hope this helps! On Mon, Jul 26, 2021, 07:54 Nick Wray <nickmw...@gmail.com> wrote: > Hello I am puzzled about the use or status of "partial" in R. years ago > I found a little piece of code which gives the pth largest number in a > vector: > x<-c(5,4,7,2,6,9) > n <- length(x) > p<-4 > sort(x,partial=n-(n-p))[n-(n-p)] > This works fine, although I have tried playing around with the code and > don't understand what "partial" is doing here. > However, wanted to work out what was going on, so I looked for "partial in > r" on t'internet and got this site:Partial apply a function, filling in > some arguments. — partial • purrr (tidyverse.org) > < > https://purrr.tidyverse.org/reference/partial.html#:~:text=Source%3A%20R%2Fpartial.R%20Partial%20function%20application%20allows%20you%20to,that%20an%20argument%20can%20only%20be%20partialised%20once > .> > Examples: > # Partial is designed to replace the use of anonymous functions for # > filling in function arguments. Instead of: compact1 <- function(x) discard > <https://purrr.tidyverse.org/reference/keep.html>(x, is.null) # we can > write: compact2 <- partial(discard, .p = is.null) # partial() works fine > with functions that do non-standard # evaluation my_long_variable <- 1:10 > plot2 <- partial(plot, my_long_variable) plot2() > when i tried to run the examples on this site I got error messages - R > (studio) did not recognise the "partial" function here. The site did not > say that I needed a particular package to run the "partial" function. > Are there essentially two different things in R both described as "partial" > but which are actually different entities? > Thanks for any elucidation > Nick Wray > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
