discretize.operators.DiffOperators.nodal_laplacian¶
- property DiffOperators.nodal_laplacian¶
Nodal scalar Laplacian operator (nodes to nodes)
This property constructs the 2nd order scalar Laplacian operator that maps from nodes to nodes. The operator is a sparse matrix \(\mathbf{L_n}\) that can be applied as a matrix-vector product to a discrete scalar quantity \(\boldsymbol{\phi}\) that lives on the nodes, i.e.:
laplace_phi = Ln @ phi
The operator
*assumes a zero Neumann boundary condition for the discrete scalar quantity. Once constructed, the operator is stored permanently as a property of the mesh.- Returns
- (
n_nodes,n_nodes)scipy.sparse.csr_matrix The numerical Laplacian operator from nodes to nodes
- (
Notes
In continuous space, the scalar Laplacian operator is defined as:
\[\psi = \nabla^2 \phi = \frac{\partial^2 \phi}{\partial x^2} + \frac{\partial^2 \phi}{\partial y^2} + \frac{\partial^2 \phi}{\partial z^2}\]Where \(\boldsymbol{\phi}\) is the discrete representation of the continuous variable \(\phi\) on the nodes, and \(\boldsymbol{\psi}\) is the discrete representation of its scalar Laplacian on the nodes, nodal_laplacian constructs a discrete linear operator \(\mathbf{L_n}\) such that:
\[\boldsymbol{\psi} = \mathbf{L_n} \, \boldsymbol{\phi}\]