find_maximum_on_interval fails when used with a sage function

[aginiewicz]

The function find_maximum_on_interval fails when used with a sage function that is passed as an argument:

sage: f(x) = sin(x)
sage: find_maximum_on_interval(f, 0, 2*pi)
Traceback (click to the left of this block for traceback)
...
RuntimeError: ECL says: THROW: The catch MACSYMA-QUIT is undefined.

while all of:

sage: find_minimum_on_interval(f, 0, 2*pi)
(-1.0, 4.7123889815323858)
sage: f.find_minimum_on_interval(0, 2*pi)
(-1.0, 4.7123889815323858)
sage: f.find_maximum_on_interval(0, 2*pi)
(1.0, 1.570796325647202)

works. This was kind of unexpected, esp that documentation says about providing a function as an argument.

[aginiewicz]

I believe this is because find_maximum_on_interval is calling find_minimum_on_interval with lambda z: -f(z) as argument (sage/numerical/optimize.py:127) and doing

     try:
         return f.find_maximum_on_interval(a=a, b=b, tol=tol,maxfun=maxfun)
     except AttributeError:
         pass

just before that should work. Am I right? This might be also related to #3955 (quite old ticket but looks like it proposes a better solution, were there some issues with it, or just no one got into it yet?). If I find enough time to make patch I will post it, but I have to recreate my build environment first (since sage 5.0 does not work with my version of gcc I switched to distribution provided package that is already patched).

[nbruin]

Dup of #12032

[novoselt]

See #2607 also.

[aginiewicz]

I looked at both of those before openning this ticket, but though #12032 is more general and not that easily fixed, and #2607 is about name/docs instead of working vs non-working. Anyway, I agree that this ticket is a duplicate (of #3955). I uploaded patch based on comment:1 there.