Re: min function very slow?

[Daniel J Sebald]

Daniel J Sebald wrote:

> John W. Eaton wrote:
>
> > 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.
>
> But how would this account for Dmitri's example in a script file where 
> upon first run it's fine and thereafter is slow?
>
> >  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).
> >  
>
> But breaking it into separate files could simply be shuffling around 
> code as well. I.e., the problem moves somewhere else.


On second thought, your hypothesis seems correct.  rand() and randn() 
are similar to max/min, being in the same file.  I rewrote the function 
with rand/randn and got similar behavior:

octave:1> [loopt, randt, randnt] = rrt(10000)
loopt = 0.10696
randt = 0.36079
randnt = 0.35501
octave:2> [loopt, randt, randnt] = rrt(10000)
loopt = 0.10461
randt = 0.34843
randnt = 7.3243