Thanks everyone for prodding my gray matter, which seems to be getting stiffer as I approach 70 (< 90 days).
-- I'll continue to use the $ or [[ forms. That will suffice. -- I thought there might be a base R variant, e.g. something like extract( list, element-name); probably cross talk in my brain from the rstan library -- Gregg's note shows such a function in purr. But I rather like having as few dependencies as possible in a package, one usage is normally not enough, at least for something this simple. Terry T. On 12/27/22 14:38, Bert Gunter wrote: > Well, I prefer Greg's approach, but if you want to avoid calls to $ or > `[[` then you could do: > > unlist(fits)[ rep(names(fits[[1]]) == 'iter', length(fits))] > > > Cheers, > Bert > > On Tue, Dec 27, 2022 at 9:46 AM Greg Snow<538...@gmail.com> wrote: >> Another option is the map family of functions in the purrr package >> (yes, this depends on another package being loaded, which may affect >> things if you are including this in your own package, creating a >> dependency). >> >> In map and friends, if the "function" is a string or integer, then it >> is taken as the piece to be extracted, so you should be able to do >> something like: >> >> library(purrr) >> map(fits, 'iter') >> # or >> map_int(fits, 'iter') >> # or >> map_dbl(fits, 'iter') >> >> which of the last 2 to use depends on how `iter` is stored. >> >> On Tue, Dec 27, 2022 at 10:16 AM Therneau, Terry M., Ph.D. via R-help >> <r-help@r-project.org> wrote: >>> I not uncommonly have the following paradym >>> fits <- lapply(argument, function) >>> >>> resulting in a list of function results. Often, the outer call is to >>> mclapply, and the >>> function encodes some long calculation, e.g. multiple chains in an MCMC. >>> Assume for illustration that each function returns a list with elements >>> beta, loglik, iter. >>> >>> Then sapply(fits, function(x) x$iter) >>> will give me a vector, with the number of iterations used by each instance. >>> >>> I've often been suspicious that there is some simple shorthand for the >>> "grab all the >>> elements named iter" that skips the explicit x$iter function. Am I indeed >>> overlooking >>> something? I don't expect a speed increase, just cleaner code. >>> >>> Terry T. >>> >>> -- >>> Terry M Therneau, PhD >>> Department of Quantitative Health Sciences >>> Mayo Clinic >>> thern...@mayo.edu >>> >>> "TERR-ree THUR-noh" >>> >>> [[alternative HTML version deleted]] >>> >>> ______________________________________________ >>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >>> https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstat.ethz.ch%2Fmailman%2Flistinfo%2Fr-help&data=05%7C01%7Ctherneau%40mayo.edu%7Cebbda887f4b94223376608dae84a58ae%7Ca25fff9c3f634fb29a8ad9bdd0321f9a%7C0%7C0%7C638077703266213025%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=wksTglkeQKmMSWWKHLsUijH5A25cH%2FuwxSNBOeNr9Sg%3D&reserved=0 >>> PLEASE do read the posting >>> guidehttps://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.r-project.org%2Fposting-guide.html&data=05%7C01%7Ctherneau%40mayo.edu%7Cebbda887f4b94223376608dae84a58ae%7Ca25fff9c3f634fb29a8ad9bdd0321f9a%7C0%7C0%7C638077703266213025%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=9GASHCZVgnzNqAUrWimS7UphiqjYLOf50M1qWv6jeN0%3D&reserved=0 >>> and provide commented, minimal, self-contained, reproducible code. >> >> >> -- >> Gregory (Greg) L. Snow Ph.D. >> 538...@gmail.com >> >> ______________________________________________ >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fstat.ethz.ch%2Fmailman%2Flistinfo%2Fr-help&data=05%7C01%7Ctherneau%40mayo.edu%7Cebbda887f4b94223376608dae84a58ae%7Ca25fff9c3f634fb29a8ad9bdd0321f9a%7C0%7C0%7C638077703266213025%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=wksTglkeQKmMSWWKHLsUijH5A25cH%2FuwxSNBOeNr9Sg%3D&reserved=0 >> PLEASE do read the posting >> guidehttps://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.r-project.org%2Fposting-guide.html&data=05%7C01%7Ctherneau%40mayo.edu%7Cebbda887f4b94223376608dae84a58ae%7Ca25fff9c3f634fb29a8ad9bdd0321f9a%7C0%7C0%7C638077703266213025%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=9GASHCZVgnzNqAUrWimS7UphiqjYLOf50M1qWv6jeN0%3D&reserved=0 >> 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.
