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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."



  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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