simpeg.electromagnetics.time_domain.Simulation3DMagneticFluxDensity.getAsubdiag#
- Simulation3DMagneticFluxDensity.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:
\[\mathbf{B}_k = -\frac{1}{\Delta t_k} \mathbf{I}\]where \(\Delta t_k\) is the step length and \(\mathbf{I}\) is the identity matrix.
See the Notes section of the doc strings for
Simulation3DMagneticFluxDensity
for a full description of the formulation.- Parameters:
- tInd
int
The time index; between
[0, n_steps-1]
.
- tInd
- Returns:
- (
n_faces
,n_faces
)sp.sparse.csr_matrix
The sub-diagonal system matrix.
- (