id,summary,reporter,owner,description,type,status,priority,milestone,component,resolution,keywords,cc,merged,author,reviewer,upstream,work_issues,branch,commit,dependencies,stopgaps
17447,Clarify and complete documentation of function(),schymans,,"The documentation of function() is incomplete and confusing.
For example, none of the methods described in http://www.sagemath.org/doc/reference/calculus/sage/symbolic/function_factory.html show up when I type:
{{{
function?
}}}
The distinction between
{{{
f = function('f')
}}}
and
{{{
f = function('f', x)
}}}
is also not documented. See also #17445 for sources of confusion. Need to explain what happens in the second case above (`f = function('f',x)`). A symbolic function `f` is first created and then overwritten by the expression `f`?
See the following example, where f is first an expression, then becomes redefined to a function in the background, but does not contain any information about its variables.
{{{
sage: f = function('f', x); print type(f)
sage: fx = function('f',x); print type(f)
sage: f.variables()
()
sage: fx.variables()
(x,)
}}}
See http://ask.sagemath.org/question/9932/how-to-substitute-a-function-within-derivatives/?answer=14752#post-id-14752 for a possible start at how to explain this, at least for those writing this.",enhancement,closed,major,sage-6.10,documentation,fixed,,nbruin kcrisman tmonteil zimmerma,,"Nils Bruin, Ralf Stephan","Ralf Stephan, Nils Bruin",N/A,,7c029f3c98032a985c2ca0329dfe940271e9b86b,7c029f3c98032a985c2ca0329dfe940271e9b86b,,