the competition's expm vs ours

[Marco Caliari]

> On Wed, Dec 3, 2008 at 1:10 AM, Jordi Gutiérrez Hermoso
> <jordigh at gmail.com> wrote:
>> 2008/12/1 Marco Caliari <marco.caliari at univr.it>:
>>> On my laptop, I got the following results for a 500x500 matrix:
>>>
>>> Octave 3.0.3 (with ATLAS): 4.3 seconds
>>> Octave 3.0.3, removing the extra steps: 4.0 seconds
>>> Matlab 7.6.0: 1.2 seconds
>>> Octave 3.0.3, rewriting in a better way the Pade' approximation (and with
>>> the extra steps): 3.7 seconds
>>>
>>> So, I don't think the extra steps produce the difference and they are
>>> suggested also in "The scaling and squaring method for the matrix
>>> exponential revisited" by N.J. Higham.
>>
>> Hrm... Are you using sources that incorporate Jaroslav's indexing
>> improvements? I guess we could profile Octave to see where the actual
>> slowdown is instead of guessing...
>>
>> - Jordi G. H.
>>
>
> Another slowdown in the m-file is caused by the fact that the expressions

Dear Jaroslav,

I computed the cputime of the builtin functions, not the m-file 
implementations.

Best regards,

Maco