Puzzled over "partial"
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 <nickmwray at 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]]
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