simpeg.electromagnetics.time_domain.Simulation3DElectricField.getAsubdiag#
- Simulation3DElectricField.getAsubdiag(tInd)[source]#
Sub-diagonal system matrix for the time-step index provided.
This method returns the sub-diagonal system matrix for the time-step index provided:
\[\mathbf{B}_k = -\frac{1}{\Delta t_k} \mathbf{M_{e\sigma}}\]where \(\Delta t_k\) is the step-length and \(\mathbf{M_{e \sigma}}\) is the conductivity inner-product matrix on edges.
See the Notes section of the doc strings for
Simulation3DElectricField
for a full description of the formulation.- Parameters:
- tInd
int
The time-step index; between
[0, n_steps-1]
.
- tInd
- Returns:
- (
n_edges
,n_edges
)sp.sparse.csr_matrix
The sub-diagonal system matrix.
- (