MATLAB memory problems

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#326

From: Ray Muzic
Date: Tue, 25 Aug 1992 17:02

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We have noticed a very undesirable behavior of MATLAB with respect to
memory managment.  This occurs on both Ultrix MATLAB (Ultrix 4.2, MATLAB
3.5f) and VAX/VMS MATLAB (VMS 5.4-3, MATLAB 3.5f).

AS we understand it, for each MATLAB assignment and for every expression or
subexpression, MATLAB allocates memory in which to store the results.
MATLAB, however, does not return the memory to the system until one exits
MATLAB. This in itself is not all that bad as it could conceiveably be done
in the interest of efficiency.  What is unforgivable, however, is that MATLAB
does not re-use this memory!

To see this for yourself, define a 512 by 512 matrix and save it to disk.
Then load the matrix into memory several times.  Between successive loads,
show memory (Ultrix: 'ps -au' or 'vmstat', VMS: 'show memory') allocation
and you will probabaly see it increase with each successive load.

Does anyone else observe this behavior on other platforms?


Ray Muzic
Ed Ellert
Don Johann
Gary Muswick




-- 
* Ray Muzic, Jr., Ph.D. | "I try not to think, it slows the progress." - rfm2 *
* muzic@ds2.uh.cwru.edu | Biomedical Engr, CWRU & Image Analysis Ctr, UH  __o *
* Voice: (216)-844-3543 | Div Nuclear Radiology, Univ Hosp of Cleveland  -\<, *
* Fax: (216)-844-3106   | 2074 Abington Rd, Cleveland, OH, 44106, USA....O/ O *

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From: muzic@ds2.uh.cwru.edu (Ray Muzic)
Newsgroups: sci.math.num-analysis
Subject: MATLAB memory problems
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Date: 25 Aug 92 17:02:05 GMT
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