[R] For Loop

Wensui Liu ||uwen@u| @end|ng |rom gm@||@com
Sun Sep 23 22:00:09 CEST 2018

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.

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.duncan using gmail.com>

> 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 :-).

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