I am unable to find out what causes this key error, but the problem is occuring when differentiation the expressions. The _xi_n variables are dummy variables introduced by sympy, see e.g https://github.com/sympy/sympy/issues/13791
Retrying to initialise the component seems to work, so this is a possible fix.
I am unable to find out what causes this key error, but the problem is occuring when differentiation the expressions. The
_xi_nvariables are dummy variables introduced by sympy, see e.g https://github.com/sympy/sympy/issues/13791Retrying to initialise the component seems to work, so this is a possible fix.
Fix #24