# SimPEG.electromagnetics.time_domain.Simulation3DMagneticField#

class SimPEG.electromagnetics.time_domain.Simulation3DMagneticField(mesh, survey=None, dt_threshold=1e-08, **kwargs)[source]#

Solve the H-J formulation of Maxwell’s equations for the magnetic field h.

We start with Maxwell’s equations in terms of the magnetic field and current density

$\nabla \times \rho \mathbf{j} + \mu \frac{\partial h}{\partial t} = \mathbf{s_m} \ \nabla \times \mathbf{h} - \mathbf{j} = \mathbf{s_e}$

and eliminate $$\mathbf{j}$$ using

$\mathbf{j} = \nabla \times \mathbf{h} - \mathbf{s_e}$

giving

$\nabla \times \rho \nabla \times \mathbf{h} + \mu \frac{\partial h}{\partial t} = \nabla \times \rho \mathbf{s_e} + \mathbf{s_m}$

Methods

 Fields_Derivs fieldsPair getAdiag(tInd) System matrix at a given time index