SimPEG.electromagnetics.natural_source.Simulation3DPrimarySecondary.getA# Simulation3DPrimarySecondary.getA(freq)[source]# System matrix \[\mathbf{A} = \mathbf{C}^{\top} \mathbf{M_{\mu^{-1}}^f} \mathbf{C} + i \omega \mathbf{M^e_{\sigma}}\] Parameters freq (float) – Frequency Return type scipy.sparse.csr_matrix Returns A