# 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