On Mon, Mar 17, 2008 at 9:40 AM, Charles R Harris <charlesr.harris@gmail.com> wrote:

OK,

Which branch do we want to use. As it currently is in numpy and scipy.special

arccosh(1.5) =  0.96242365011920694
arccosh(1.5+0j) =  -0.96242365011920705 + 0.0j

This is consistent with gsl, but inconsistent with Mathematica, NAG, Maple, and probably all sensible implementations which use the generally accepted principal value. I've left this inconsistency raising an error in the ufunc tests until we make a decision. It might be nice to know what FORTRAN and MatLab do with this.

Chuck

_______________________________________________
Numpy-discussion mailing list
Numpy-discussion@scipy.org
http://projects.scipy.org/mailman/listinfo/numpy-discussion