Table of Contents
Name | Direction | Type | Default | Description |
---|---|---|---|---|
InputWorkspace | Input | MatrixWorkspace | Mandatory | Input workspace containing the data to fit by LeBail algorithm. |
OutputWorkspace | Output | Workspace2D | Output workspace containing calculated pattern or calculated background. | |
InputParameterWorkspace | Input | TableWorkspace | Mandatory | Input table workspace containing the parameters required by LeBail fit. |
OutputParameterWorkspace | Output | TableWorkspace | Input table workspace containing the parameters required by LeBail fit. | |
InputHKLWorkspace | Input | TableWorkspace | Mandatory | Input table workspace containing the list of reflections (HKL). |
OutputPeaksWorkspace | Output | TableWorkspace | Optional output table workspace containing all peaks’ peak parameters. | |
WorkspaceIndex | Input | number | 0 | Workspace index of the spectrum to fit by LeBail. |
FitRegion | Input | dbl list | Region of data (TOF) for LeBail fit. Default is whole range. | |
Function | Input | string | LeBailFit | Functionality. Allowed values: [‘LeBailFit’, ‘Calculation’, ‘MonteCarlo’, ‘RefineBackground’] |
PeakType | Input | string | ThermalNeutronBk2BkExpConvPVoigt | Peak profile type. Allowed values: [‘ThermalNeutronBk2BkExpConvPVoigt’, ‘NeutronBk2BkExpConvPVoigt’] |
BackgroundType | Input | string | Polynomial | Background type. Allowed values: [‘Polynomial’, ‘Chebyshev’, ‘FullprofPolynomial’] |
BackgroundParameters | Input | dbl list | Optional: enter a comma-separated list of background order parameters from order 0. | |
BackgroundParametersWorkspace | InOut | TableWorkspace | Optional table workspace containing the fit result for background. | |
PeakRadius | Input | number | 5 | Range (multiplier relative to FWHM) for a full peak. |
PlotIndividualPeaks | Input | boolean | False | Option to output each individual peak in mode Calculation. |
IndicationPeakHeight | Input | number | 0 | Heigh of peaks (reflections) if its calculated height is smaller than user-defined minimum. |
UseInputPeakHeights | Input | boolean | True | For ‘Calculation’ mode only, use peak heights specified in ReflectionWorkspace. Otherwise, calcualte peaks’ heights. |
Minimizer | InOut | string | Levenberg-MarquardtMD | The minimizer method applied to do the fit, default is Levenberg-Marquardt. Allowed values: [‘BFGS’, ‘Conjugate gradient (Fletcher-Reeves imp.)’, ‘Conjugate gradient (Polak-Ribiere imp.)’, ‘Damping’, ‘FABADA’, ‘Levenberg-Marquardt’, ‘Levenberg-MarquardtMD’, ‘Simplex’, ‘SteepestDescent’] |
Damping | Input | number | 1 | Damping factor if minizer is ‘Damping’ |
NumberMinimizeSteps | Input | number | 100 | Number of Monte Carlo random walk steps. |
MCSetupWorkspace | Input | TableWorkspace | Name of table workspace containing parameters’ setup for Monte Carlo simualted annearling. | |
RandomSeed | Input | number | 1 | Randum number seed. |
AnnealingTemperature | Input | number | 1 | Temperature used Monte Carlo. Negative temperature is for simulated annealing. |
UseAnnealing | Input | boolean | True | Allow annealing temperature adjusted automatically. |
DrunkenWalk | Input | boolean | False | Flag to use drunken walk algorithm. Otherwise, random walk algorithm is used. |
MinimumPeakHeight | Input | number | 0.01 | Minimum height of a peak to be counted during smoothing background by exponential smooth algorithm. |
AllowDegeneratedPeaks | Input | boolean | False | Flag to allow degenerated peaks in input .hkl file. Otherwise, an exception will be thrown if this situation occurs. |
ToleranceToImportPeak | Input | number | Optional | Tolerance in TOF to import peak from Bragg peaks list. If it specified, all peaks within Xmin-Tol and Xmax+Tol will be imported. It is used in the case that the geometry parameters are close to true values. |
This algorithm performs Le Bail Fit to powder diffraction data, and also supports pattern calculation. This algorithm will refine a specified set of the powder instrumental profile parameters with a previous refined background model.
Here is the list of the peak profile function supported by this algorithm.
Here is the list of the peak profile function supported by this algorithm.
LeBailFit supports a tailored simulated annealing optimizer (using Monte Carlo random walk algorithm). In future, regular minimizes in GSL library might be supported.