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 :-).
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