From: Gerard Jungman <jungman@lanl.gov>
To: gsl-discuss@sourceware.org
Subject: Re: GSL containers (switched sparse format to binary trees)
Date: Fri, 02 May 2014 01:56:00 -0000 [thread overview]
Message-ID: <5362FB2A.7090608@lanl.gov> (raw)
In-Reply-To: <5362F944.9090408@lanl.gov>
As before, I apologize for the flood of messages.
But I figure better a few shorter messages than
one long message with multiple sub-topics.
Here is another discussion that I found interesting:
http://comments.gmane.org/gmane.comp.lib.gsl.general/4385
As usual, the details could be debated. But I found the
following quote to be very telling:
"Rhys, I did try to use views. They do not help because the
gsl routines allocate vectors internally and there is not
much that I can do about it... except for maybe hacking
gsl and changing gsl_vector_alloc myself."
People seem to be led to this conclusion from multiple
directions.
Another choice quote:
"The other issue is: the implementation of gsl_vector just
seems inefficient to me. Looking at the code, it seems like
a single vector requires 3 calls to malloc and free (one for
the data, one for the gsl_block, and one for the gsl_vector
itself). The manual states that the block is there for
"consistency", and I can see how memory management becomes
easier with it. But it seems to be a case of generality at
the expense of performance. Also, the stride and the owner
flag are part of the gsl_vector object to make it work with
gsl_views, but then people who never need views pay the
performance price anyway."
next prev parent reply other threads:[~2014-05-02 1:56 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-28 1:32 switched sparse format to binary trees Patrick Alken
2014-04-28 22:35 ` Gerard Jungman
2014-04-29 1:13 ` Patrick Alken
2014-04-29 8:40 ` Frank Reininghaus
2014-04-29 19:15 ` Gerard Jungman
2014-04-29 19:52 ` Patrick Alken
2014-04-29 22:07 ` Gerard Jungman
2014-05-01 18:46 ` Patrick Alken
2014-05-01 23:21 ` Gerard Jungman
2014-05-02 1:48 ` GSL containers (switched sparse format to binary trees) Gerard Jungman
2014-05-02 1:56 ` Gerard Jungman [this message]
2014-05-02 8:29 ` Rhys Ulerich
2014-05-02 8:33 ` Rhys Ulerich
2014-05-02 8:52 ` Rhys Ulerich
2014-05-02 15:02 ` Patrick Alken
2014-05-13 21:59 ` Gerard Jungman
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