How to define a generic function?

[Mattia Villani]

I am trying to calculate the general expression of the Kretschmann scalar of  metric depending a non specified function m(r): how do I define such a function? II have tried with

def m(r)

but it is wrong since it expects a definition of the function

[Dima Pasechnik]

just added some keywords to the subject.

[Eric Gourgoulhon]

Simply use

mr = function('m')(r)

See

https://nbviewer.jupyter.org/github/sagemanifolds/SageManifolds/blob/master/Worksheets/v1.3/SM_TOV.ipynb

for a full example.

Best wishes,

Eric.