# SimPEG.maps.ChiMap#

class SimPEG.maps.ChiMap(mesh=None, nP=None, **kwargs)[source]#

Mapping that computes the magnetic permeability given a set of magnetic susceptibilities.

Where $$\boldsymbol{\chi}$$ is the input model parameters defining a set of magnetic susceptibilities, ChiMap creates a mapping $$\boldsymbol{\mu}(\boldsymbol{\chi})$$ that computes the corresponding magnetic permeabilities of every element in $$\boldsymbol{\chi}$$; i.e.:

$\boldsymbol{\mu}(\boldsymbol{\chi}) = \mu_0 \big (1 + \boldsymbol{\chi} \big )$

where $$\mu_0$$ is the permeability of free space.

Parameters
meshdiscretize.BaseMesh

The number of parameters accepted by the mapping is set to equal the number of mesh cells.

nPint

Set the number of parameters accepted by the mapping directly. Used if the number of parameters is known. Used generally when the number of parameters is not equal to the number of cells in a mesh.

Methods

 deriv(m[, v]) Derivative of mapping with respect to the input parameters. Apply the inverse mapping to an array.