On Oct. 3, Raymond Toy wrote:
> Edwin Woollett wrote:
>> the present Maxima help manual has quad_qags default
>> value for epsrel as 1d-10.
>>
>> The actual default appears to be 1d-8 based on
>> the following.
>>
> The manual is wrong. The default is 1d-8, which can be determined by
> looking at the source code.
>
> Thanks for pointing it out.
>
> Ray
>
Thanks for reminding me of the greatest advantage (for the serious
researcher) of
Maxima (as compared with Mathematica and Maple): namely, if one's
program is not behaving as expected, one can always look at the
Maxima source code which is being used for that program, and see exactly
what
is going on (transparency vs. black box).
Even for a programmer literate only in fortran 77, one can get a good idea
of the sequence of actions by looking at the lisp code and following the
trail of the function calls.
For interested Maxima users, the file to look at is
..../src/numerical/slatec/quadpack.lisp, which can
be compared to the fortran code contained in
quadpack.f on the webpage
http://people.scs.fsu.edu/~burkardt/f77_src/quadpack/quadpack.html
I personally need to pay more attention to the open source advantage
as I learn about Maxima.
Ted Woollett