From maintainers-request at octave dot org Sun Jan 30 00:57:12 2005
Subject: Re: min function very slow?
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: "Dmitri A. Sergatskov" <dmitri at unm dot edu>
Cc: Daniel J Sebald <daniel dot sebald at ieee dot org>, maintainers@octave.org
Date: Sun, 30 Jan 2005 00:56:11 -0600

On 29-Jan-2005, Dmitri A. Sergatskov <dmitri at unm dot edu> wrote:

| Daniel J Sebald wrote:
| 
| >> octave:1> minmaxtime
| >> looptime = 0.035128
| >> maxtime = 0.065962
| >> mintime = 0.30040
| >>
| >> Regards,
| >>
| >> Dmitri
| >>
| >> p.s. 2.1.64 + octave-forge-2004.11.16 / athlonMP 2000 MHz
| > 
| > Thank you... so do you think your increase for mintime is a blip in the 
| > OS?  Yours is a factor of 4.5 difference, mine is a factor of 76.
| 
| I do not understand this at all. More over on my other computer (AthlonXP 1666 MHz)
| the mintime is 2 seconds... The same OS etc...

If you have min and max in .oct files, then they are really defined in
the same file (minmax.oct) and the min.oct and max.oct files are just
additional links in the filesystem.  It seems that the second one
loaded is much slower.  I think this must be some accidental overhead
in checking whether the symbol needs to be reloaded.  The problem goes
away for me if I define min and max in separate files (i.e., create
min.cc and max.cc, each with only one DEFUN_DLD macro) or if I set
ignore_function_time_stamp = "all" (I'm not sure why setting it to
"system" fails, even when the min/max functions are installed in a
"system" directory).

I'll try to check it out more thoroughly.  I'm traveling, so it may
be a week or so before I can get to it, so if someone else can pin it
down more completely (point out the code that is wrong), that would
help.

Thanks,

jwe