>>>>> "Barton" == Barton Willis writes:
[snip]
Barton> (5) Since we last talked about such things, GCL has fixed some bugs in
Barton> its acosh function; see
Barton> (there may be other important messages, but I can't find them right now)
Barton> http://www.math.utexas.edu/pipermail/maxima/2002/002955.html
Barton> http://www.math.utexas.edu/pipermail/maxima/2002/002949.html
Barton> Maybe 5.9.3 would be a good time to:
Barton> (a) make the Maxima acosh function the same as the CL acosh function.
Yes.
Barton> (b) move numerical evaluation for exponetial-like
Barton> functions to CL. Then Maxima would not have to use
Barton> rectform to evaluate things like sin(1.0 + 5.0 * %i).
I've done some of this for the elliptic functions. One question:
What should maxima do with sin(1 + 5.0*%i)? Leave it? Apply "numeric
contagion" and pretend it was sin(1.0+5.0*%i) and evaluate
numerically, even without the numer or float flags?
Barton> (c) check for other branch cut inconsistencies.
I think this is important and we should do that soon.
Let me also add that we should try to evaluate the special functions
as accurately as possible, even for bigfloats. sinh is one example
where we do not do a very good job for small x. In the thread
mentioned above, we also do not evaluate acosh(4100) very well either.
(We should fix the problem that eps is too small in trigi.lisp.)
Also, in the thread mentioned above, we talked about letting Lisp
evaluate the functions. One thing that needs to be considered is what
to do about signed zeroes. Should maxima support that? My current
(highly uninformed) feeling is not to support signed zeroes. If so,
we will need to exercise a little care when calling Lisp functions for
evaluation because cmucl and sbcl support signed zeroes.
Ray