You can wrap lambdify into a new function:
def get_lambda(expr, modules="numpy", **kwargs):
from sympy.utilities.iterables import ordered
signature = list(ordered(expr.free_symbols))
return signature, lambdify(signature, expr, modules=modules, **kwargs)
With it, the argument are sorted alphabetically. You can easily see the
list of arguments by printing signature.
Davide.
Il giorno gio 9 lug 2020 alle ore 11:08 Roberto <
franceschini.robe...@gmail.com> ha scritto:
> I have seen that lambdify wants a list for the arguments to be treated as
> symbols. This list can be also give as a python set, e.g. {x,y,z }, which
> is exactly what would be returned by a .free_symbol property. If lambdify
> is feed a set like that of the output of .free_symbol it may change their
> order in the conversion from set to list. This is done silently and may
> cause major disfunction in the use of the lamdified function because you
> think x is x, but is y instead and so on.
> I would like to ask developers to check for the type of the lambdify list
> of arguments and throw a warning to flag that a set is being converted and
> that the ordering is not guaranteed.
> Given that .free_symbols returns a set, not a list, this is very common
> pitfall in my opinion and must be prevented.
>
> --
> You received this message because you are subscribed to the Google Groups
> "sympy" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to sympy+unsubscr...@googlegroups.com.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/sympy/c1517b79-490b-4a1b-b526-3e3842b55fbco%40googlegroups.com
> <https://groups.google.com/d/msgid/sympy/c1517b79-490b-4a1b-b526-3e3842b55fbco%40googlegroups.com?utm_medium=email&utm_source=footer>
> .
>
--
You received this message because you are subscribed to the Google Groups
"sympy" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to sympy+unsubscr...@googlegroups.com.
To view this discussion on the web visit
https://groups.google.com/d/msgid/sympy/CAO%3D1Z09sTVnnD3jxJi4UdDDkis7R5Dwh8NHDY0PMOYESmK79gA%40mail.gmail.com.
