id summary reporter owner description type status priority milestone component resolution keywords cc merged author reviewer upstream work_issues branch commit dependencies stopgaps
24428 Numerical evaluation should return a complex number if applicable jdemeyer "This looks wrong:
{{{
sage: arccosh(0.9)
NaN
}}}
Especially given all the following:
{{{
sage: arccosh(RDF(0.9))
0.45102681179626236*I
}}}
{{{
sage: arccosh(x).subs(x=0.9)
0.451026811796262*I
}}}
{{{
sage: sqrt(-2.0)
1.41421356237310*I
}}}
A complex number is more useful than a `NaN` so we shouldn't return `NaN` in the first example.
The `Function` code first calls `x.arccosh()` which returns the `NaN`. The reason for only the RDF case working is that RDF does not have a `arccosh` member function so the computation is delegated to Pynac where the complex value is returned." defect needs_work major sage-8.2 symbolics rws slelievre Ralf Stephan N/A u/rws/24428 aa041a972d4b09a1e8b771b370e57f9f9ac19f7b #24832, pynac-0.7.17