`conversions`

Note

conversions is also available under nexus. For example, nx.conversions.DegToRad(degree) is also available as nx.DegToRad(degree).

Module for conversions of physical properties and units.

nexus.conversions.AngleToQ(angle, energy)

Converts the grazing scattering angle to absolute of the \(q\)-vector.

Added in version 1.0.3.

Parameters:

angle (float or list) – angle(s) to be converted (rad).
energy (float) – X-ray energy (eV).

Returns:

absolute of the \(q\)-vector (1/m).

Return type:

float

nexus.conversions.AtToWt(composition)

Convert material composition given in at% to wt%.

in atomic composition: composition = ([‘Fe’, 2], [‘O’, 3]) for Fe ₂ O ₃

or in at%: composition = ([‘Fe’, 0.4], [‘O’, 0.6])

Parameters:: composition (list) – ([‘A’, x], [‘B’, y], …) where A, B, … are element strings and x, y, … is the fraction in atomic composition or at%.
Returns:: composition with x, y, … in wt%
Return type:: list

nexus.conversions.DegToMrad(degree)

Conversion from degree to milliradians.

Parameters:: degree (double) – angle in degree.
Returns:: angle in millirad.
Return type:: double

nexus.conversions.DegToRad(degree)

Conversion from degree to radians.

Parameters:: degree (double) – angle in degree.
Returns:: angle in rad.
Return type:: double

nexus.conversions.DegToUrad(degree)

Conversion from degree to microradians.

Parameters:: degree (double) – angle in degree.
Returns:: angle in microrad.
Return type:: double

nexus.conversions.EnergyToKvector(energy)

Conversion from energy to photon k-vector.

Parameters:: energy (double) – energy in eV.
Returns:: k-vector in 1/m.
Return type:: double

nexus.conversions.EnergyToKvectorZ(energy, angle)

Conversion from energy to photon k-vector along z direction in grazing incidence direction.

Parameters:

energy (double) – energy in eV.
angle (double) – angle in degree.

Returns:

k-vector along z direction in 1/m.

Return type:

double

nexus.conversions.EnergyToVelocity(energy, isotope)

Convert a Doppler detuning from energy to velocity.

Changed in version 1.2.0: Conversion error corrected.

Parameters:

energy (float or list or ndarray) – Energy in eV.
isotope (MoessbauerIsotope) – Moessbauer isotope of the experiment.

Returns:

Velocity detuning in mm/s.

Return type:

float or list or ndarray

nexus.conversions.EnergyToWavelength(energy)

Conversion from energy to photon wavelength.

Parameters:: energy (double) – energy in eV.
Returns:: wavelength in meter.
Return type:: double

nexus.conversions.FwhmToSigma(fwhm): Returns sigma of a Gaussian from its Full Width Half Maximum (FWHM).

nexus.conversions.GammaToVelocity(energy, isotope)

Convert a Doppler detuning from energy in units of the linewidth to velocity.

Parameters:

energy (float or list or ndarray) – Energy in units of the linewidth (\(\Gamma\)).
isotope (MoessbauerIsotope) – Moessbauer isotope of the experiment.

Returns:

Velocity detuning in mm/s.

Return type:

float or list or ndarray

nexus.conversions.KvectorToEnergy(kvector)

Conversion from photon k-vector to energy.

Parameters:: kvector (double) – k-vector in 1/m.
Returns:: energy in eV.
Return type:: double

nexus.conversions.MagSphericalToVector(mag, theta, phi, angle='deg')

Calculates the magnetic field in Nexus frame (\(\sigma\), \(\pi\), k) to spherical coordinates.

Added in version 1.0.2.

Parameters:

mag (float) – magnetic field \(\sigma\) component.
theta (float) – polar angle.
phi (float) – azimuthal angle.
angle (string) – Units of the input angles, “rad” or “deg”.

Returns:

\(\sigma\) component, \(\pi\) component, k component.

Return type:

float, float, float

nexus.conversions.MagVectorToSpherical(sigma, pi, k, angle='deg')

Calculates the magnetic field in spherical coordinates from an input vector in the Nexus frame (\(\sigma\), \(\pi\), k).

Added in version 1.0.2.

Parameters:

sigma (float) – \(\sigma\) component.
pi (float) – \(\pi\) component.
k (float) – k component.
angle (string) – Units of the returned angles, “rad” or “deg”.

Returns:

magnitude, polar angle, azimuthal angle.

Return type:

float, float, float

nexus.conversions.MradToDeg(mrad)

Conversion from milliradians to degree.

Parameters:: mrad (double) – angle in millirad.
Returns:: angle in degree.
Return type:: double

nexus.conversions.QToAngle(q, energy)

Converts the absolute of the \(q\)-vector to the grazing scattering angle.

Added in version 1.0.3.

Parameters:

q (float or list) – absolute of the \(q\)-vector(s) (1/m).
energy (float) – X-ray energy (eV).

Returns:

grazing scattering angle (rad).

Return type:

float

nexus.conversions.RadToDeg(rad)

Conversion from radians to degree.

Parameters:: rad (double) – angle in rad.
Returns:: angle in degree.
Return type:: double

nexus.conversions.SigmaToFwhm(sigma): Returns the Full Width Half Maximum (FWHM) from Gaussian sigma value.

nexus.conversions.UradToDeg(urad)

Conversion from microradians to degree.

Parameters:: urad (double) – angle in microrad.
Returns:: angle in degree.
Return type:: double

nexus.conversions.VelocityToEnergy(velocity, isotope)

Convert a Doppler detuning from velocity to energy.

Parameters:

velocity (float or list or ndarray) – velocity in mm/s.
isotope (MoessbauerIsotope) – Moessbauer isotope of the experiment.

Returns:

Energy detuning in eV.

Return type:

float or list or ndarray

nexus.conversions.VelocityToGamma(velocity, isotope)

Convert a Doppler detuning from velocity to energy in units of the linewidth.

Parameters:

velocity (float or list or ndarray) – Velocity in mm/s.
isotope (MoessbauerIsotope) – Moessbauer isotope of the experiment.

Returns:

Energy detuning in units of the linewidth (\(\Gamma\)).

Return type:

float or list or ndarray

nexus.conversions.WavelengthToEnergy(wavelength)

Conversion from photon wavelength to energy.

Parameters:: wavelength (double) – wavelength in meter.
Returns:: energy in eV.
Return type:: double

nexus.conversions.WtToAt(composition)

Convert material composition given in wt% to at%.

in wt%: composition = ([‘Fe’, 0.699], [‘O’, 0.301]) for Fe ₂ O ₃

Parameters:: composition (list) – ([‘A’, x], [‘B’, y], …) where A, B, … are element strings and x, y, … is the fraction in wt%.
Returns:: composition with x, y, … in at%
Return type:: list

Examples

angle = 2100  # in microrad
print(nx.conversions.UradToDeg(angle))

angle = 40  # in degree
print(nx.DegToMrad(angle))

velocity = np.linspace(-10, 10, 201)  # mm/s

detuning = nx.conversions.VelocityToGamma(velocity, nx.moessbauer.Fe57)

comp = (['Fe', 2], ['O', 3])

comp = nx.conversions.AtToWt(comp)
print(comp)

comp = nx.conversions.WtToAt(comp)
print(comp)

comp = (['Fe', 0.4], ['O', 0.6])

comp = nx.converions.AtToWt(comp)
print(comp)

comp = nx.conversions.WtToAt(comp)
print(comp)

conversions

`conversions`