[Openmcl-devel] Maxima + Clozure on Windows

[Barton Willis]

-----Gary Byers <gb at clozure.com> wrote: -----

>Barton (and anyone else who might know):
>
>1) is doing
>
>bessel_j(3,2.0);
>
>in Maxima equivalanet to doing
>
>(maxima::bessel-j 3 2.0)
>
>in lisp ?

Yes, that is correct.

>2) is the correct answer approximately 0.129 ?  (That's what I get
>in an x86-64 CCL.)

Yes, the correct value is 0.1289432494744. Alternatively, you can skip
maxima::bessel-j and go directly to slatex:desj; for example:

Maxima 5.17post http://maxima.sourceforge.net
Using Lisp Clozure Common Lisp Version 1.3-dev-r11537M-trunk
(WindowsX8632)
(%i1) to_lisp();
Type (to-maxima) to restart, ($quit) to quit Maxima.
MAXIMA> (setf jvals (make-array 4 :element-type
'double-float :initial-element 0.0d0))
#(0.0 0.0 0.0 0.0)
MAXIMA> (slatec:dbesj 2.0 0.0 4 jvals 0)

NIL
NIL
NIL
NIL
0
MAXIMA> jvals
#(0.0 0.0 0.0 0.0)
MAXIMA>

The array jvals should be

  #(0.22389077914123579 0.57672480775687363 0.35283402861563784
  0.12894324947440208)

>If so, then we may have a reproducible test case that demonstrates
>at least one problem; the bad news is that the problem is likely
>in the Maxima function SLATEC::DBESJ. which seems to have been
>automatically translated from Fortran and is rather large (about 17KB
>of source, about 32KB of object code.)  It might be necessary to
>sort of whack at that from both ends in order to expose the bug.

The supporting code in f2cl-lib could also be to blame.

I know that automatically translated function SLATEC::DBESJ isn't a simple
test
case, but it's the best I've been able to do. I'll keep looking.

It's terrific that you all are interested in fixing this bug. Thanks.

Barton