From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: Any easy/build-in construct to extract submatrices from larger matrix?
Date: Sun, 24 Jun 2012 10:24:36 +0200
Date: 2012-06-24T10:24:36+02:00 [thread overview]
Message-ID: <nrn0zo41ylee.3jz8xvqubzuv$.dlg@40tude.net> (raw)
In-Reply-To: js6hof$o9g$1@speranza.aioe.org
On Sun, 24 Jun 2012 03:05:37 -0500, Nasser M. Abbasi wrote:
> fyi, modern Fortran has a nice facility to do this, called
> pack(). It works like this: make up a MASK matrix of same size
> as A. For those elements we want removed, put in a logical
> .false at that location.
This looks like a low-level hack with unpredictable results, because it
does not specify the dimensions and the order of the elements for the
result matrix.
If I implemented indicator functions for matrices, with the thingy is, I
would define an abstract type with multiple implementations including a set
of indices. A set would be far more effective for sparse matrices than
Boolean matrix.
--
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
next prev parent reply other threads:[~2012-06-24 8:24 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-24 8:05 Any easy/build-in construct to extract submatrices from larger matrix? Nasser M. Abbasi
2012-06-24 8:24 ` Dmitry A. Kazakov [this message]
2012-06-24 8:55 ` Nasser M. Abbasi
2012-06-24 11:10 ` Dmitry A. Kazakov
2012-06-24 12:16 ` Nasser M. Abbasi
2012-06-24 16:11 ` Dmitry A. Kazakov
2012-06-24 17:14 ` Nasser M. Abbasi
2012-06-24 18:33 ` Dmitry A. Kazakov
2012-06-25 5:44 ` J-P. Rosen
2012-06-25 6:32 ` Nasser M. Abbasi
2012-06-25 7:54 ` J-P. Rosen
2012-06-25 8:20 ` Dmitry A. Kazakov
2012-06-25 14:21 ` Nasser M. Abbasi
2012-06-25 8:36 ` Georg Bauhaus
2012-06-25 13:17 ` Nasser M. Abbasi
2012-06-26 11:44 ` Georg Bauhaus
2012-06-25 16:49 ` Pascal Obry
2012-06-25 17:36 ` Nasser M. Abbasi
2012-06-25 18:49 ` stefan-lucks
2012-06-26 4:41 ` Nasser M. Abbasi
2012-06-26 7:15 ` Jacob Sparre Andersen
2012-06-26 9:51 ` Nasser M. Abbasi
2012-06-25 9:33 ` Simon Wright
2012-06-26 2:48 ` Jerry
2012-06-26 4:19 ` Nasser M. Abbasi
2012-06-26 7:06 ` Nasser M. Abbasi
2012-06-26 12:54 ` Robert A Duff
2012-06-26 15:19 ` Adam Beneschan
2012-06-26 21:14 ` Robert A Duff
2012-06-27 23:42 ` Shark8
2012-06-26 7:10 ` Dmitry A. Kazakov
2012-06-26 15:06 ` Adam Beneschan
2012-06-26 21:19 ` Robert A Duff
2012-06-26 21:40 ` Adam Beneschan
2012-07-03 4:22 ` Randy Brukardt
2012-07-03 8:37 ` Dmitry A. Kazakov
2012-07-05 1:33 ` Randy Brukardt
2012-07-05 7:08 ` Dmitry A. Kazakov
2012-07-06 23:47 ` Randy Brukardt
2012-07-07 8:22 ` Dmitry A. Kazakov
2012-07-05 18:56 ` Adam Beneschan
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