is it possible to create custom nodes for the geometry node editor (NOT node groups, combining blender built-in nodes), define inputs and outputs and execute some python code in between? I couldn't find any information about completely userdefined nodes nor tutorials anywhere.
Further information about the usecase:
I want to create a node, which executes a more elaborate python code involving some linear algebra and finding eigenvalues of matrices. Therefore I created a python code using scipy, installed the scipy package in blender and I am already able to execute it within blender in the scripting environment and it outputs the correct values in the system console. Now I want to take the input values from a geometry node (position in x and y), calculate the output value of my python function and assign it as a z coordinate to all my verticies.