`EnergyTimeSpectrum`

class nexus.EnergyTimeSpectrum(experiment, time_length=200, time_step=0.2, mode='i', electronic=False, time_data=[], intensity_data=[[]], scaling='auto', background=0.0, energy_resolution=0.0, time_resolution=0.7, distribution_points=1, fit_weight=1.0, bunch_spacing=inf, residual=<nexus.clib.cnexus.Sqrt; proxy of <Swig Object of type 'Residual *'> >, id='')

Bases: FitMeasurement

Constructor for the EnergyTimeSpectrum class. Class to calculate the energy and time-dependent intensity of the experiment. One sample has to have a drive detuning.

Parameters:

id (string) – User identifier.
experiment (Experiment) – Experiment.
time_length (float) – Length of the calculation in nanoseconds.
time_step (float) – Step size of the calculation in nanoseconds.
mode (string) –
Identifier for the calculation mode.
- i Interpolate detuning values. Fast mode.
- f Full calculation via change of the isomer shift. Slow mode.
electronic (bool) – If True electronic scattering is also included.
time_data (list or ndarray) – Time data for fitting.
intensity_data (ndarray) – 2D intensity data for fitting. 1st dimension detuning, 2nd dimension time.
scaling (float or Var or string) – Intensity scaling factor for fitting. Default is auto.
background (float or Var or string) – Background for fitting. Default is 0.
energy_resolution (float or Var) – Energy resolution value for convolution.
time_resolution (float or Var) – Time resolution value for convolution.
distribution_points (int) – Number of points for thickness distributions in forward geometry and angular divergence in grazing geometry. Both distributions assume incoherent summation over the weighted contributions. Default is 1.
fit_weight (float) – Relative weight for the cost function in multi measurement fitting.
bunch_spacing (float) – Spacing of subsequent X-ray bunches in time (nanoseconds).
residual (Residual) – Implementation of the residual calculation used for fitting.

id

User identifier.

Type:: string

experiment

Experiment

Type:: Experiment

time_length

Length of the calculation in nanoseconds.

Type:: float

time_step

Step size of the calculation in nanoseconds.

Type:: float

electronic

If True electronic scattering is also included.

Type:: bool

mode

Identifier for the calculation mode.

i: interpolate detuning values, fast mode.
f: full calculation via change of the isomer shift.

Type:: string

time_data

Time data for fitting.

Type:: list

intensity_data

2D intensity data for fitting. 1st dimension detuning, 2nd dimension time.

Type:: array

data_size

Number of data points of experimental data.

Type:: int

scaling

Intensity scaling factor for fitting.

Type:: Var

background

Intensity background for fitting.

Type:: Var

energy_resolution

Energy resolution value used for the convolution. The energy resolution is not the energy resolution of the drive sample (e.g. an analyzer foil). This intrinsic resolution is given by the energy spectrum of drive sample. The energy resolution specified here is an additional energy resolution due to the experimental conditions, like an in proper drive motion itself.

Type:: Var

time_resolution

Time resolution value for convolution.

Type:: Var

resolution_kernel

Weight of 2D Gaussian resolution. Same step size as detuning.

Type:: array

distribution_points

Number of points for thickness distributions in forward geometry and angular divergence in grazing geometry. Both distributions assume incoherent summation over the weighted contributions.

Type:: int

fit_weight

Relative weight for the cost function in multi measurement fitting.

Type:: float

bunch_spacing

Spacing of subsequent X-ray bunches in time (nanoseconds).

Type:: float

residual

Implementation of the residual calculation used for fitting.

Type:: Residual

result

Array of intensity values in units of (\(\Gamma/ns\)).

Type:: ndarray

drive_sample

Sample with drive detuning.

Added in version 1.0.3.

Changed in version 2.0.0: changed from old Sample class to BasicSample.

Type:: BasicSample

Calculate()

Calculates the class method. Also callable via operator ().

Returns:: 2D array of intensities.
Return type:: ndarray

Cost()

Get the cost function of the measurement

\[cost = \frac{1}{n} \sum_i r(y_i, \hat{y}_i)\]

Added in version 2.0.0.

Returns:: cost function value.
Return type:: float

MeanSquaredError()

Get the mean squared error (MSE) of the measurement

\[cost = \frac{1}{n} \sum_i (y_i - \hat{y}_i)^2\]

Added in version 2.0.0.

Returns:: MSE value.
Return type:: float

Plot(): Plot the EnergyTimeSpectrum.

Added in version 1.0.3.

Velocity()

Returns the velocity detuning of the measurement in units of mm/s.

Returns:: Velocity detuning (mm/s).
Return type:: ndarray

EnergyTimeSpectrum

`EnergyTimeSpectrum`