Set initial conditions for tensor-element

[dokken]

@InfiniteElement

Why do you square the mesh.geometry.dim?

As a Tensor element will have 3 * 3 entries if you use a cell with geometric/topological dimension 3.
The shape of values should be equal to the flattened version of the the tensor, i.e. values[0] = tensor[0,0], values[1] = tensor[0,1], values[2] = tensor[0,2], values[3] = tensor[1,0] etc.

@InfiniteElement

Why do you assign only values[0] up to values[3], when values has a length of 9?

Because this was just to illustrate to you how you should assign values for each component of the tensor.

@InfiniteElement

• Which part of values exactly do I have to target to assign the identity matrix to F, i.e. the second function-part?

Then you should create values with zeros, as I already showed

@dokken

    values = np.zeros((mesh.geometry.dim*mesh.geometry.dim,
                      x.shape[1]), dtype=np.float64)

and set

values[0,:] = 1
values[3,:] = 1
values[6,:] = 1

You should verify this by writing F to file after interpolating data into it.