id,summary,reporter,owner,description,type,status,priority,milestone,component,resolution,keywords,cc,merged,author,reviewer,upstream,work_issues,branch,commit,dependencies,stopgaps
6376,serious bug in _maxima_init_ method for formal derivatives with new symbolics,was,burcin,"{{{
sage: f(x) = function('f',x)
sage: g = f(-x).diff(x); g
-D[0](f)(-x)
sage: g._maxima_init_()
""(diff('f(x), x, 1))*(-1)""
}}}
Notice that the {{{-x}}} inside f is totally ignored! This is because of code in the derivative method around line 454 of {{{sage/symbolic/expression_conversion.py}}}
Changing the line
{{{
args = ex.args()
}}}
to
{{{
args = ex.operands()
}}}
""fixes"" the problem, in that a NotImplementedError gets raised, instead of a wrong result returned. This is '''way''' better than the current situation, and we better fix this asap.
A better fix of course is to implement proper conversion. mhansen wrote this code, so maybe it would be easy for him.
",defect,closed,critical,sage-duplicate/invalid/wontfix,calculus,duplicate,,gmhossain mhansen,,,,,,,,,