Here are a couple of quick examples that may help: > 1:10 [1] 1 2 3 4 5 6 7 8 9 10 > 10:1 [1] 10 9 8 7 6 5 4 3 2 1 > pmax( 10:1, 1:10 ) [1] 10 9 8 7 6 6 7 8 9 10 > pmin( 1:10, 5 ) [1] 1 2 3 4 5 5 5 5 5 5
In the first example with pmax, there are 2 vectors being compared (10-1, 1-10), so first 10 is compared to 1 and since 10 is larger it is the first element of the returned vector, then 9 is compared to 2 and 9 becomes the second element, this continues till the 10th comparison is 1 vs. 10 and 10 is the final element. The second (pmin) example shows the recycling, each of the numbers 1-10 is compared to the number 5, in each case the smaller of the pair is returned (1-4 for the first 4 elements, then 5 for the rest). Hope this helps, -- 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-boun...@r- > project.org] On Behalf Of rkevinbur...@charter.net > Sent: Monday, January 12, 2009 5:55 PM > To: r-help@r-project.org > Subject: [R] pmax and sort? > > I am having a hard time understanding the documentation and I was > wondering if there would be someone to help clear the cobwebs. > > The documentation for pmax states: > > pmax and pmin take one or more vectors (or matrices) as arguments and > return a single vector giving the ‘parallel’ maxima (or minima) of the > vectors. The first element of the result is the maximum (minimum) of > the first elements of all the arguments, the second element of the > result is the maximum (minimum) of the second elements of all the > arguments and so on. Shorter inputs are recycled if necessary. > attributes (such as names or dim) are transferred from the first > argument (if applicable). > > This descirption seems to me like what sort would return. Would someone > please help me understand the differenece between pmax and sort? > > Thank you. > > Kevin > > ______________________________________________ > 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.
