id summary reporter owner description type status priority milestone component resolution keywords cc merged author reviewer upstream work_issues branch commit dependencies stopgaps
9881 fix the symbolic csgn function on complex input burcin burcin "Our wrapper of the csgn function from GiNaC (in `sage/symbolic/expression.pyx`) doesn't reflect it's real definition:
{{{
/** Return the complex half-plane (left or right) in which the number lies.
* csgn(x)==0 for x==0, csgn(x)==1 for Re(x)>0 or Re(x)=0 and Im(x)>0,
* csgn(x)==-1 for Re(x)<0 or Re(x)=0 and Im(x)<0.
* */
}}}
Fix this and add doctests.
We should also consider using GiNaC's `csgn()` function for the top level `sgn()` and `sign()` functions. This should be on a different ticket though." defect closed major sage-4.6 symbolics fixed pynac sage-4.6.alpha3 Burcin Erocal Karl-Dieter Crisman N/A