Tensors

The tensors are represented using the Tensor class, which is a custom class for storing symbolic tensors, which uses the sympy library under the hood.

To print the tensor use the pprint method of the class, for example, for tensor X:

X.pprint()

will print the tensor.

To access the individual component of the tensor use normal python indexing, with indices starting from 0, such as:

X[0,1]

The components of the tensor are sympy expression and thus sympy functionalities can be used. For example, to multiply a conductivity tensor by electric field to get the resultant current, you can use:

import sympy as sp

X = res[0]

j = sp.zeros(1,3)
Ex,Ey,Ez = sp.symbols('Ex Ey Ez')
E = sp.Matrix([Ex,Ey,Ez])
for i in range(3):
    for k in range(3):
        j[i] += X[i,k] * E[k]