# SimPEG.maps.ExpMap#

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

Mapping that computes the natural exponentials of the model parameters.

Where $$\mathbf{m}$$ is a set of model parameters, ExpMap creates a mapping $$\mathbf{u}(\mathbf{m})$$ that computes the natural exponential of every element in $$\mathbf{m}$$; i.e.:

$\mathbf{u}(\mathbf{m}) = exp(\mathbf{m})$

ExpMap is commonly used when working with physical properties whose values span many orders of magnitude (e.g. the electrical conductivity $$\sigma$$). By using ExpMap, we can invert for a model that represents the natural log of a set of physical property values, i.e. when $$m = log(\sigma)$$

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 of the exponential mapping to an array.

## Galleries and Tutorials using SimPEG.maps.ExpMap#

Maps: ComboMaps

Maps: ComboMaps

3D DC inversion of Dipole Dipole array

3D DC inversion of Dipole Dipole array

Parametric DC inversion with Dipole Dipole array

Parametric DC inversion with Dipole Dipole array

2D inversion of Loop-Loop EM Data

2D inversion of Loop-Loop EM Data

EM: TDEM: 1D: Inversion

EM: TDEM: 1D: Inversion

EM: TDEM: 1D: Inversion with VTEM waveform

EM: TDEM: 1D: Inversion with VTEM waveform

FLOW: Richards: 1D: Forward Simulation

FLOW: Richards: 1D: Forward Simulation

FLOW: Richards: 1D: Inversion

FLOW: Richards: 1D: Inversion

Heagy et al., 2017 1D RESOLVE and SkyTEM Bookpurnong Inversions

Heagy et al., 2017 1D RESOLVE and SkyTEM Bookpurnong Inversions

Heagy et al., 2017 1D RESOLVE Bookpurnong Inversion

Heagy et al., 2017 1D RESOLVE Bookpurnong Inversion

Heagy et al., 2017 Casing Example

Heagy et al., 2017 Casing Example

Heagy et al., 2017 1D FDEM and TDEM inversions

Heagy et al., 2017 1D FDEM and TDEM inversions

1D Inversion of for a Single Sounding

1D Inversion of for a Single Sounding

Tensor Meshes

Tensor Meshes

Cylindrical Meshes

Cylindrical Meshes

Tree Meshes

Tree Meshes

2.5D DC Resistivity and IP Least-Squares Inversion

2.5D DC Resistivity and IP Least-Squares Inversion

3D Least-Squares Inversion of DC and IP Data

3D Least-Squares Inversion of DC and IP Data

Least-Squares 1D Inversion of Sounding Data

Least-Squares 1D Inversion of Sounding Data

Sparse 1D Inversion of Sounding Data

Sparse 1D Inversion of Sounding Data

Parametric 1D Inversion of Sounding Data

Parametric 1D Inversion of Sounding Data

2.5D DC Resistivity Least-Squares Inversion

2.5D DC Resistivity Least-Squares Inversion

2.5D DC Resistivity Inversion with Sparse Norms

2.5D DC Resistivity Inversion with Sparse Norms

3D Least-Squares Inversion of DC Resistivity Data

3D Least-Squares Inversion of DC Resistivity Data

1D Inversion of Time-Domain Data for a Single Sounding

1D Inversion of Time-Domain Data for a Single Sounding