proposal to change acosh



>>>>> "Barton" == Barton Willis  writes:

    Barton> -----Raymond Toy wrote: -----

    >> 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> I suggest we adopt "numeric contagion."  One argument

Yes, it's a simple rule that everyone is familiar with---everything is
converted to the largest float type.

    Barton> Since 1.0 * %i --> %i, numeric contagion has a problem:
    Barton> cos(1 + 1.0 * %i) --> cos(1 + %i), yet cos(1 + 1.0001 * %i) -->
    Barton> complex double float.  Sigh.

Hmm.  That is a problem.  I suppose we could turn off the conversion
of 1.0*%i to %i.

    Barton> (c) check for other branch cut inconsistencies.
    >> 
    >> I think this is important and we should do that soon.

    Barton> I'll work on this.

Great!  I'll look into bigfloat evaluation of sinh and friends.

Ray