Error by the mixfunction

[dokken]

Please format your code appropriately using 3x` encapsulation.

For your particular problem, it seems like you are trying to interpolate initial conditions into a sub space.

To do this you should interpolate into the collapsed sub space, and in turn use FunctionAssigner.
See for instance:

Usage of FunctionAssigner

As you are working with a 3 dimensional mesh, the vector function space has three components: T_S_1 = interpolate(S_11, T) T_S_2 = interpolate(S_12, T) T_s_0 = Function(T) # Function containing 0 values assigner = FunctionAssigner(V, [T, T, T]) assigner.assign(v, [T_S_1, T_S_2, T_s_0])