bfieldtools.thermal_noise.noise_covar_dir

bfieldtools.thermal_noise.noise_covar_dir(B_coupling, vl, Nmodes=None)

Calculates (AC or DC) magnetic noise covariance between x, y and z directions from the modes vl.

Parameters

B_coupling: ndarray (Np, 3, Nvertices)

Magnetic field coupling matrix from the mesh

vl: ndarray (Nvertices, Nmodes, x Nfreqs) or (Nvertices, Nmodes)

The Johnson noise current modes on the mesh

Nmodes: int

How many modes are included? If None, all modes in vl are included

Returns

Bcov: ndarray (Np, 3, 3, Nfreqs) or (Np, 3, 3)

Magnetic noise covariance x, y and z field components