Hi,
I also observed such slowdown over time, with completely
different computations (I'm also using Ecl; don't know whether
it has to do with that).
Oliver
P.S. The slowdown can become very drastic, a factor of 10 or so.
On Tue, Mar 01, 2011 at 05:29:37PM -0800, Nils Bruin wrote:
> Dear maxima developers,
>
> This was observed with Maxima 5.23.2 on ECL 11.1.1 on 64bit linux:
>
> The following code shows a progressive slowdown:
>
> assume(y>1);
> while true do block([t,I,j],
> t: absolute_real_time(),
> for j: 1 step 1 thru 100 do I: integrate(log(x^2+y^2),x,0,1),
> print(absolute_real_time()-t));
>
> Typical output is something like:
>
> 13
> 17
> 24
> 30
>
> But this doesn't occur for all integrals, for instance for:
>
> while true do block([t,I,j],
> t: absolute_real_time(),
> for j: 1 step 1 thru 1000 do I: integrate(cos(x^2)*sin(x),x),
> print(absolute_real_time()-t));
>
> we get the flat behaviour one would hope for:
>
> 24
> 25
> 26
> 25
> 25
>
> Is there a good reason for this behaviour? Is this only for ECL? Does it
> point to a leak somewhere?
>
> Kind regards,
>
> Nils Bruin
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