Tried the following -
class f(Function):
is_real = True
x = symbols('x',real=True)
F = f('F',x)
print f
print re(f)
print im(f)
df = F.diff(x)
print re(df)
print im(df)
and got -
f
f
0
re(D{x}f)
im(D{x}f)
Again it works for the function, but not the derivatives of the function.
On Sat, Sep 19, 2015 at 7:37 PM, Alan Bromborsky <[email protected]>
wrote:
> Then how do I instanciate a real function of several variables as in
>
> X = symbols('x y z',real=True)
>
> F = Function('F')(*X)
>
> On Sat, Sep 19, 2015 at 6:34 PM, Christophe Bal <[email protected]>
> wrote:
>
>> Hello.
>>
>> Have you tried this ?
>>
>>
>> *from sympy import **
>>
>> *class f(Function):*
>> * is_real = True*
>>
>> *x = Symbol('x',real=True)*
>>
>> *df = f.diff(x)*
>>
>> *print(re(df))*
>> *print(im(df))*
>>
>>
>>
>>
>> *Christophe BAL*
>> *Enseignant de mathématiques en Lycée **et développeur Python amateur*
>> *---*
>> *French math teacher in a "Lycée" **and **Python **amateur developer*
>>
>> 2015-09-20 0:22 GMT+02:00 brombo <[email protected]>:
>>
>>> Could you elucidate further or give me a link. I don't have a clue to
>>> implement what you suggested.
>>>
>>> On Saturday, September 19, 2015 at 6:00:11 PM UTC-4, Aaron Meurer wrote:
>>>>
>>>> The only way to do it presently is to subclass Function manually:
>>>>
>>>> class f(Function):
>>>> is_real = True
>>>>
>>>> Aaron Meurer
>>>>
>>>> On Sat, Sep 19, 2015 at 2:47 PM, brombo <[email protected]> wrote:
>>>> > Your method works for a function, but not the derivative of a
>>>> function -
>>>> >
>>>> > x = Symbol('x',real=True)
>>>> >
>>>> > f = RealFunction('f')(x)
>>>> >
>>>> > print re(f)
>>>> > f
>>>> > print im(f)
>>>> > 0
>>>> >
>>>> > df = f.diff(x)
>>>> > print re(df)
>>>> > re(df)
>>>> > print im(df)
>>>> > im(df)
>>>> >
>>>> > What should happen is that re(df) = df and im(df) = 0, but is doesn't
>>>> > happen. Any suggestions?
>>>> >
>>>> >
>>>> >
>>>> >
>>>> > On Saturday, September 19, 2015 at 12:58:53 PM UTC-4, brombo wrote:
>>>> >>
>>>> >> How do I define a real function of a real variable?
>>>> >>
>>>> >> X = symbols('x y z',real=True)
>>>> >>
>>>> >> f = Function('f',real=True)(*X)
>>>> >>
>>>> >> "real=True" in Function doesn't do anything.
>>>> >
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>>>>
>>>> >
>>>> > For more options, visit https://groups.google.com/d/optout.
>>>>
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