"... I learned to say "try it and see" in many different ways. "
Version 2: *Never* parallelize your computations .... except when you should. ;-) -- Bert On Sun, Sep 23, 2018 at 1:20 PM Duncan Murdoch <murdoch.dun...@gmail.com> wrote: > On 23/09/2018 4:00 PM, Wensui Liu wrote: > > Very insightful. Thanks, Duncan > > > > Based on your opinion, is there any benefit to use the parallelism in > > the corporate computing environment where the size of data is far more > > than million rows and there are multiple cores in the server. > > I would say "try it and see". Sometimes it probably helps a lot, > sometimes it's probably detrimental. > > Duncan Murdoch > > P.S. I last worked in a corporate computing environment 40 years ago > when I was still wet behind the ears, so you'd probably want to ask > someone else. However, more recently I worked in an academic > environment where I learned to say "try it and see" in many different > ways. You just got the basic one today. > > > > > > Actually the practice of going concurrency or not is more related to my > > production tasks instead of something academic. > > > > Really appreciate your thoughts. > > > > On Sun, Sep 23, 2018 at 2:42 PM Duncan Murdoch <murdoch.dun...@gmail.com > > <mailto:murdoch.dun...@gmail.com>> wrote: > > > > On 23/09/2018 3:31 PM, Jeff Newmiller wrote: > > > > [lots of good stuff deleted] > > > > > Vectorize is > > > syntactic sugar with a performance penalty. > > > > [More deletions.] > > > > I would say Vectorize isn't just "syntactic sugar". When I use that > > term, I mean something that looks nice but is functionally > equivalent. > > > > However, Vectorize() really does something useful: some functions > > (e.g. > > outer()) take other functions as arguments, but they assume the > > argument > > is a vectorized function. If it is not, they fail, or generate > garbage > > results. Vectorize() is designed to modify the interface to a > function > > so it acts as if it is vectorized. > > > > The "performance penalty" part of your statement is true. It will > > generally save some computing cycles to write a new function using a > > for > > loop instead of using Vectorize(). But that may waste some > > programmer time. > > > > Duncan Murdoch > > (writing as one of the authors of Vectorize()) > > > > P.S. I'd give an example of syntactic sugar, but I don't want to > bruise > > some other author's feelings :-). > > > > ______________________________________________ > 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.
