Implement point source in the variational formulation

variational formulation
2

The Expression approach should be modified as follows

class Delta(UserExpression):
    def __init__(self, eps, **kwargs):
        self.eps = eps
        UserExpression.__init__(self, **kwargs) 
    def eval(self, values, x):
        eps = self.eps
        values[0] = eps/pi/(np.linalg.norm(x)**2 + eps**2)
        values[1] = 0
        values[2] = 0

    def value_shape(self): return (3, )
3 Likes