3.3.3.158. NXstress¶
Status:
application definition, extends NXobject
Description:
Application definition for stress and strain analysis of crystalline material de ...
Application definition for stress and strain analysis of crystalline material defined by the EASI-STRESS consortium.
When a crystal is loaded (applied or residual stress) its crystallographic parameters change.
Stress and strain analysis calculates deformation (strain) and the associated force (stress) from diffraction data.
This application definition essentially standardizes the result of diffraction pattern analysis from different types of diffraction experiments for the purpose of stress and strain analysis. The analysis is typically some form of diffraction peak indexing and fitting. The experiments are for example
energy-dispersive X-ray powder diffraction
angular-dispersive X-ray powder diffraction
angular-dispersive neutron powder diffraction
time-of-flight (TOF) neutron powder diffraction.
In addition, the application definition guarantees that the information about instrumental setups, measurement conditions, and data analysis workflows are described. This ensures not only the reproducability and tracability of the measured data, but also the meta-data. Since not all participating beamlines or instruments can provide an input to all the NXfields listed in this application definition, not all of them are “required”. However, when possible and technically feasible, the instrument using the NXstress application definition is expected to provide the type of information outlined below.
Sample and detector positions can be defined with NXtransformations. If you don’t specify the direction of gravity and the direction of the beam then the standard NeXus Coordinate System is used.
It is highly recommended that in case certain parameters or values are the same for all the measurements (acquistions) in the same file, that they are stored only in one location and then linked in the other instances. For example, if during an acquisition all instrumental parameters but one stay the same and only the sample table moves in one direction (e.g. Xtranslation), then all the static instrumental parameters should be saved just once (e.g. in just one NXentry or in a Shared_Information group) and their vales linked to every instrument group under all the other acquistions. The value for the variable that changes, Xtranslation in this example, is suggested to only be saved at every instrument group under each acquistion but not in the Shared_Information group. It is not always necessary to link each field. In case all the fields with an entire group are the same, the entire group can be linked.
Symbols:
nX: Number of diffractogram channels.
nD: Number of diffractograms. For example the number of energy-dispersive detectors or the number of azimuthal sections in an area detector.
nPeaks: Number of reflections.
xUnit: Diffractogram X units.
yUnit: Diffractogram Y units.
cUnit: Converted diffractogram X units (could be the same as xUnit).
- Groups cited:
NXbeam, NXcollection, NXdata, NXdetector, NXentry, NXinstrument, NXnote, NXprocess, NXreflections, NXsample, NXsource, NXtransformations, NXuser
Structure:
ENTRY: (required) NXentry
The name of the NXentry group(s) can be freely chosen by the facility. The NXentry group can contain any form of data acquisition (e.g. a measurement point, multiple measurement points, a line scan, a mesh, all data points from one sample …).
definition: (required) NX_CHAR ⤆
Official NeXus NXDL schema to which this file conforms ...
Official NeXus NXDL schema to which this file conforms
Obligatory value:
NXstress
Extended title for the entry.
experiment_identifier: (optional) NX_CHAR ⤆
Unique identifier for the experiment as defined by the facility (e.g. DOI, proposal id, …). At ILL, this could be, for example,
exp_1-02-286
,exp_INDU-229
, orexp_INTER-569
.experiment_description: (optional) NX_CHAR ⤆
Brief summary of the experiment, including key objectives. At least one of t ...
- Brief summary of the experiment, including key objectives. At least one of the following information should be provided:
energy-dispersive X-ray powder diffraction
angular-dispersive X-ray powder diffraction
angular-dispersive neutron powder diffraction
time-of-flight (TOF) neutron powder diffraction
start_time: (required) NX_DATE_TIME ⤆
The starting time(s) of measurement(s) which can be provided in form of a list if multiple measurements are included in the same NXentry.
end_time: (required) NX_DATE_TIME ⤆
The end time(s) of measurement(s) which can be provided in form of a list if multiple measurements are included in the same NXentry.
collection_identifier: (optional) NX_CHAR ⤆
User or Data Acquisition defined identifier from which ...
User or Data Acquisition defined identifier from which the content of this application definition is derived. This can be freely chosen by the user or the instrument scientist and could be, for example,
05_DA_650_AX_B3P5
,SENB-14
,Quartz
,….collection_description: (optional) NX_CHAR ⤆
Brief summary of the collection, including grouping criteria. The information provided in this field can highlight, for example, the measurement setup or information about experimental conditions.
diffraction_type: (required) NX_CHAR
This variable describes the type of data plotted in the diffractogram and de ...
- This variable describes the type of data plotted in the diffractogram and describes the type of calculation used in the EASI-STRESS software. Any of these values are valid:
two-theta
energy
d-spacing
sin2psi
measurement_direction: (optional) NX_CHAR
Describes the specific measurement direction covered by the data in this fil ...
- Describes the specific measurement direction covered by the data in this file. Any of these values are valid:
radial
longitudinal
normal
tangential
multiple
experiment_responsible: (optional) NXuser ⤆
instrument: (required) NXinstrument ⤆
Name of the diffractometer, instrument, or beamline used for the experiment. This could be, for example, Strain Analyser for Large and Small scale engineering Applications.
@short_name: (optional) NX_CHAR ⤆
Short name for the instrument, perhaps the acronym, which would be for the the example above
SALSA
.CALIBRATION: (optional) NXnote
Geometry and/or efficiency measurement(s).
calibration_type: (required) NX_CHAR
Describe the type of calibration
file_name: (optional) NX_CHAR ⤆
Name of the calibration file
Calibration file content.
Mime content type of note data field e.g. text/plain, application/json
Author or creator of note
date: (optional) NX_DATE_TIME ⤆
Date note created/added
Type of radiation source (pick one from the enumerated list and spell ex ...
- Type of radiation source (pick one from the enumerated list and spell exactly)
- Any of these values:
Spallation Neutron Source
Pulsed Reactor Neutron Source
Reactor Neutron Source
Synchrotron X-ray Source
Rotating Anode X-ray
Fixed Tube X-ray
Metal Jet X-ray
Type of radiation probe (pick one from the enumerated list and spell exa ...
- Type of radiation probe (pick one from the enumerated list and spell exactly)
Any of these values:
neutron
|X-ray
energy: (optional) NX_FLOAT {units=NX_ENERGY} ⤆
Source energy. The energy should be provided in keV, but if chosen other ...
Source energy. The energy should be provided in keV, but if chosen otherwise, the units must be clearly specified. For storage rings, this would be the particle beam energy. For X-ray tubes, this would be the excitation voltage. In case of energy dispersive diffraction, the
wavelength: (optional) NX_FLOAT
In case of monochromatic radiation, the wavelength used during the experiment. The wavelength should be provided in \(\unicode{x212B}\), but if chosen otherwise, the units must be clearly specified.
DETECTOR: (required) NXdetector ⤆
Zero or more of these groups describe the detectors used in the experiment.
description: (optional) NX_CHAR ⤆
name/manufacturer/model/etc. information
Description of type such as 3He gas cylinder, 3He PSD, scintillator, fission chamber, proportion counter, ion chamber, CCD, pixel, image plate, CMOS, …
distance: (optional) NX_NUMBER {units=NX_LENGTH}
This is the distance to the previous component in the ...
This is the distance to the previous component in the instrument; most often the sample. The usage depends on the nature of the detector: Most often it is the distance of the detector assembly. But there are irregular detectors. In this case the distance must be specified for each detector pixel.
efficiency: (optional) NX_FLOAT (Rank: 2, Dimensions: [i, j]) {units=NX_DIMENSIONLESS}
efficiency of the detector
wavelength: (optional) NX_FLOAT (Rank: 2, Dimensions: [i, j]) {units=NX_WAVELENGTH}
This field can be two things: ...
This field can be two things:
1. For a pixel detector it provides the nominal wavelength for which the detector has been calibrated.
2. For other detectors this field has to be seen together with the efficiency field above. For some detectors, the efficiency is wavelength dependent. Thus this field provides the wavelength axis for the efficiency field. In this use case, the efficiency and wavelength arrays must have the same dimensionality.
dead_time: (optional) NX_FLOAT (Rank: 3, Dimensions: [nP, i, j]) {units=NX_TIME} ⤆
Detector dead time
count_time: (optional) NX_NUMBER (Rank: 1, Dimensions: [nP]) {units=NX_TIME} ⤆
Elapsed actual counting time
depends_on: (optional) NX_CHAR ⤆
The axis on which the detector position depends may be stored ...
The axis on which the detector position depends may be stored anywhere, but is normally stored in the NXtransformations group within the NXdetector group.
TRANSFORMATIONS: (optional) NXtransformations ⤆
This is the recommended location for detector goniometer ...
This is the recommended location for detector goniometer and other related axes.
beam_intensity_profile: (required) NXbeam ⤆
Defines the dimensions of the beam profile used for probing the sample whi ...
Defines the dimensions of the beam profile used for probing the sample which corresponds to or can be used to determine the instrumental gauge volume. A description of the subsequent fields can be found in the folowing figure. The term “primary” in the subsequent fields refers to the beam path between the sample and the source. The term “secondary” refers to the beam path between the sample and the detector(s).
beam_evaluation: (optional) NX_CHAR
If the beam profile was measured, the filename(s) of the measurement can be specified here.
primary_vertical_type: (optional) NX_CHAR
Defines the last device right in front of the sample used to shape the beam. This could be, for example, a (radial) collimator or a slit.
primary_vertical_source_width: (optional) NX_NUMBER
Defines the primary beam size intensity profile on the side closer to the source in the vertical direction.
primary_vertical_sample_width: (optional) NX_NUMBER
Defines the primary beam size intensity profile on the side closer to the sample in the vertical direction.
primary_vertical_distance: (optional) NX_NUMBER
Defines the distance between the center of the gauge volume and the beam shaping device.
primary_vertical_evaluation: (optional) NX_CHAR
Describes how the beam intensity profile in the primary vertical direction was determined. Examples of valid entries are:
measured
,theoretical
,estimated
, …primary_horizontal_type: (optional) NX_CHAR
Defines the last device right in front of the sample used to shape the beam. This could be, for example, a (radial) collimator or a slit.
primary_horizontal_source_width: (optional) NX_NUMBER
Defines the primary beam size intensity profile on the side closer to the source in the horizontal direction.
primary_horizontal_sample_width: (optional) NX_NUMBER
Defines the primary beam size intensity profile on the side closer to the sample in the horizontal direction.
primary_horizontal_distance: (optional) NX_NUMBER
Defines the distance between the center of the gauge volume and the beam shaping device.
primary_horizontal_evaluation: (optional) NX_CHAR
Describes how the beam intensity profile in the primary horizontal direction was determined. Examples of valid entries are:
measured
,theoretical
,estimated
, …secondary_horizontal_type: (optional) NX_CHAR
Defines the last device right in front of the sample used to shape the beam. This could be, for example, a (radial) collimator or a slit.
secondary_horizontal_detector_width: (optional) NX_NUMBER
Defines the secondary beam size intensity profile on the side closer to the detector in the horizontal direction.
secondary_horizontal_sample_width: (optional) NX_NUMBER
Defines the secondary beam size intensity profile on the side closer to the sample in the horizontal direction.
secondary_horizontal_distance: (optional) NX_NUMBER
Defines the distance between the center of the gauge volume and the beam shaping device.
secondary_horizontal_evaluation: (optional) NX_CHAR
Describes how the beam intensity profile in the secondary horizontal direction was determined. Examples of valid entries are:
measured
,theoretical
,estimated
, …sample_description: (required) NXsample ⤆
This is the recommended location for describing parameters associated with the sample.
Descriptive name of sample
chemical_formula: (optional) NX_CHAR ⤆
The chemical formula specified using CIF conventions. ...
The chemical formula specified using CIF conventions. Abbreviated version of CIF standard:
Only recognized element symbols may be used.
Each element symbol is followed by a ‘count’ number. A count of ‘1’ may be omitted.
A space or parenthesis must separate each cluster of (element symbol + count).
Where a group of elements is enclosed in parentheses, the multiplier for the group must follow the closing parentheses. That is, all element and group multipliers are assumed to be printed as subscripted numbers.
Unless the elements are ordered in a manner that corresponds to their chemical structure, the order of the elements within any group or moiety depends on whether or not carbon is present.
If carbon is present, the order should be:
C, then H, then the other elements in alphabetical order of their symbol.
If carbon is not present, the elements are listed purely in alphabetic order of their symbol.
This is the Hill system used by Chemical Abstracts.
temperature: (optional) NX_FLOAT (Rank: anyRank, Dimensions: [n_Temp]) {units=NX_TEMPERATURE} ⤆
Sample temperature. This could be a scanned variable
stress_field: (optional) NX_FLOAT (Rank: 1, Dimensions: [n_sField]) {units=NX_ANY} ⤆
gauge_volume: (optional) NXcollection
The gauge volume can be described with the following parameters: ...
- The gauge volume can be described with the following parameters:
x: (optional) NX_FLOAT {units=NX_LENGTH}
Length of the first diagonal.
y: (optional) NX_FLOAT {units=NX_LENGTH}
Length of the second diagonal normal to a.
z: (optional) NX_FLOAT {units=NX_LENGTH}
Height of the gauge volume.
depends_on: (optional) NX_CHAR
The axis on which the sample position depends may be stored ...
The axis on which the sample position depends may be stored anywhere, but is normally stored in the NXtransformations group within the NXsample group.
TRANSFORMATIONS: (optional) NXtransformations ⤆
This is the recommended location for sample goniometer ...
This is the recommended location for sample goniometer and other related axes.
Zero or more groups to describe the data processing steps ...
Zero or more groups to describe the data processing steps to obtain the content of this application definition.
raw_data_file: (required) NX_CHAR
The raw data file name(s) used during the data reduction process. This can be a list.
date: (required) NX_DATE_TIME ⤆
Date when the raw data was reduced and the data in the NXstress file format generated.
Software package used to perform data reduction including the version number or release date.
integration_type: (optional) NX_CHAR
Describes how the data was integrated.
bins: (optional) NX_CHAR
Describes the type of binning used during data reduction.
fit_type: (optional) NX_CHAR
Describes how the fitting of the peaks was done. For example, single peak fit, multiple peak fit, Pawley refinement, Rietveld refinement, …
fit_range: (optional) NX_CHAR
Describes the data range used for peak fitting.
goodness_of_fit: (optional) NX_CHAR
Type and value describing the goodness of fit. For example, Rw 0.23.
normalization: (optional) NX_CHAR
Describes whether the data was normalized and if so , how. Examples of valid entries are:
None
,time
,primary monitor
,detector
, …data_reduction_responsible: (optional) NXuser
description: (required) NXnote ⤆
The note will contain information about how the data was processed ...
The note will contain information about how the data was processed or anything about the data provenance. The contents of the note can be anything that the processing code can understand, or a simple text.
The name will be numbered to allow for ordering of steps.
peak_parameters: (required) NXdata
This group contains all diffraction peak fit parameters. ...
This group contains all diffraction peak fit parameters. This information is not required for stress and strain calculations. Note that as in any NXdata group, each field can have uncertainties associated to them (e.g. center_errors would be the uncertainties on the peak center).
Diffraction peak profile. ...
Diffraction peak profile.
Any of these values:
gaussian
lorentzian
voigt
pseudo-voigt
split pseudo-voigt
pearson VII
area: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_ANY}
Diffraction peak area (not including the background) in yUnit units.
@units: (required) NX_CHAR
Specify the yUnit units
height: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_ANY}
Diffraction peak height (not including the background) in yUnit units.
@units: (required) NX_CHAR
Specify the yUnit units
fwhm: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_ANY}
Diffraction peak full width at half maximum in xUnit units.
@units: (required) NX_CHAR
Specify the xUnit units
fwhm_left: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_ANY}
Left-side FWHM for split profiles in xUnit units.
@units: (required) NX_CHAR
Specify the xUnit units
fwhm_right: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_ANY}
Right-side FWHM for split profiles in xUnit units.
@units: (required) NX_CHAR
Specify the xUnit units
form_factor: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_DIMENSIONLESS}
- Voigt or Pseudo-Voigt: Lorentzian fraction ...
Voigt or Pseudo-Voigt: Lorentzian fraction
Pearson VII: decay parameter
Other profiles: not applicable
form_errors: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_DIMENSIONLESS}
Error value(s) asscociated with the form_factor.
azimuth: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_ANGLE}
Angle that define the position of the integrated sector in the diffracti ...
Angle that define the position of the integrated sector in the diffraction cone for angular-dispersive diffraction or the position of the detector for energy-dispersive diffraction.
background_parameters: (required) NXdata
This group contains all background fit parameters. ...
This group contains all background fit parameters. This information is not required for stress and strain caluclations.
Diffraction background profile. Required when background parameter field ...
Diffraction background profile. Required when background parameter fields are present. Some example values with equations are shown below:
manual
: No equations nor variables needed to describe this background.
linear
: \(\small background= A0 + A1 \cdot x\)
5-degree polynomial
: \(\small background= A0 + A1 \cdot x + A2 \cdot \mathrm{x}^{2} + A3 \cdot \mathrm{x}^{3} + A4 \cdot \mathrm{x}^{4} + A5 \cdot \mathrm{x}^{5}\)
shape function plus polynomial
: A shape function is not a mathematical function, it contains a manual background obtained from a fit and a polynomial part. This allows to adapt and modify the fit for subsequent measurements in the same measurement campaign. The function describing it is the following: \(\small background= as + b \cdot SHAPE(x-o)\) Where SHAPE is the name of the variable used to describe the background value at the position x. x can be e.g. the scattering angle \(2\theta\) in degrees.A: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_DIMENSIONLESS}
Background parameter(s). For example a second-degree polynomial will have fields
A0
,A1
andA2
.as: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_DIMENSIONLESS}
Background parameter constant for SHAPE function.
as_errors: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_DIMENSIONLESS}
Error associated with background parameter constant for SHAPE function.
b: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_DIMENSIONLESS}
Background parameter amplitude for SHAPE function.
b_errors: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_DIMENSIONLESS}
Error associated with background parameter amplitude for SHAPE function.
o: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_DIMENSIONLESS}
Background parameter offset for SHAPE function.
o_errors: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_DIMENSIONLESS}
Error associated with background parameter offset for SHAPE function.
background_area: (optional) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_ANY}
The background area in yUnit units, integrated over a confidence interval around the center (0.95 by default).
@units: (required) NX_CHAR
Specify the yUnit units
background_area_interval: (optional) NX_DIMENSIONLESS
Confidence interval from which the background counts are integrated. ...
Confidence interval from which the background counts are integrated. For example 0.95 means that the background is integrated over the range in which the integrated peak area is 95% of the total peak area.
DIFFRACTOGRAM: (required) NXdata
Diffractogram with fit results in :ref:`peak_parameters
Diffractogram with fit results in peak_parameters and background_parameters. This information is not required for stress and strain caluclations.
List of the one to two axes field name(s) to be used by default. The axes are further described in the fields DAXIS and XAXIS.
Default field name to be plotted. ...
Default field name to be plotted.
Obligatory value:
diffractogram
@auxiliary_signals: (required) NX_CHAR ⤆
List of additional field names to be plotted. This could be e.g. fit, background, residuals, …
DAXIS: (optional) NX_CHAR (Rank: 1, Dimensions: [nD])
One or more fields that contain the values for the **nD** dimension. ...
One or more fields that contain the values for the nD dimension. For example the azimuthal positions of different energy-dispersive detectors or the average azimuth of different azimuthal sections on an area detector.
XAXIS: (required) NX_NUMBER (Rank: 1, Dimensions: [nX]) {units=NX_ANY}
One or more fields that contain the values for the **nX** dimension in * ...
One or more fields that contain the values for the nX dimension in xUnit units. For example: MCA channels, scattering angle \(2\theta\) in degrees, scattering vector length q in \(\mathrm{nm}^{-1}\), …
@units: (required) NX_CHAR
Specify the xUnit units
diffractogram: (required) NX_NUMBER (Rank: 2, Dimensions: [nD, nX]) {units=NX_ANY}
diffractogram_errors: (required) NX_NUMBER (Rank: 2, Dimensions: [nD, nX]) {units=NX_ANY}
fit: (required) NX_NUMBER (Rank: 2, Dimensions: [nD, nX])
Diffractogram fit counts (auxiliary signal).
@interpretation: (required) NX_CHAR
Obligatory value:
spectrum
fit_errors: (required) NX_NUMBER (Rank: 2, Dimensions: [nD, nX])
Diffractogram fit counts error (auxiliary signal).
background: (optional) NX_NUMBER (Rank: 2, Dimensions: [nD, nX])
In case the diffraction background was manually determined. Diffractogram background counts (auxiliary signal).
@interpretation: (required) NX_CHAR
Obligatory value:
spectrum
residuals: (optional) NX_NUMBER (Rank: 2, Dimensions: [nD, nX])
Difference between diffractogram and fit (auxiliary signal).
@interpretation: (required) NX_CHAR
Obligatory value:
spectrum
User description of the data acquisitions. ...
User description of the data acquisitions. A description of data analysis goes in the fig_log group.
peaks: (required) NXreflections
This group contains all diffraction peak parameters that could be needed for ...
This group contains all diffraction peak parameters that could be needed for stress and strain calculations. These parameters are derived from peak_parameters and additional metadata.
h: (required) NX_INT (Rank: 1, Dimensions: [nPeaks]) {units=NX_UNITLESS}
First Miller index.
k: (required) NX_INT (Rank: 1, Dimensions: [nPeaks]) {units=NX_UNITLESS}
Second Miller index.
l: (required) NX_INT (Rank: 1, Dimensions: [nPeaks]) {units=NX_UNITLESS}
Third Miller index.
lattice: (optional) NX_CHAR (Rank: 1, Dimensions: [nPeaks])
Crystal lattice systems (cubic, hexagonal, …)
space_group: (optional) NX_CHAR (Rank: 1, Dimensions: [nPeaks])
Crystallographic space group \((Fm\bar{3}m, Im\bar{3}m, ...)\)
phase_name: (required) NX_CHAR (Rank: 1, Dimensions: [nPeaks])
Name of the crystallographic phase (hematite, goethite, a-Al2O3, …).
qx: (required) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_DIMENSIONLESS}
First component of the *normalized* scattering vector *Q* in the sample re ...
First component of the normalized scattering vector Q in the sample reference frame. The sample reference frame is defined by the sample transformations.
qy: (required) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_DIMENSIONLESS}
Second component of the *normalized* scattering vector *Q* in the sample r ...
Second component of the normalized scattering vector Q in the sample reference frame. The sample reference frame is defined by the sample transformations.
qz: (required) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_DIMENSIONLESS}
Third component of the *normalized* scattering vector *Q* in the sample re ...
Third component of the normalized scattering vector Q in the sample reference frame. The sample reference frame is defined by the sample transformations.
center: (required) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_ANY}
Diffraction peak position in cUnit units.
@units: (required) NX_CHAR
Specify the *cUnit* units (see :ref:`center_type
Specify the cUnit units (see center_type)
Any of these values:
degrees
: two-theta
keV
: energy
1/angstrom
: momentum-transfer
angstrom
: d-spacing
microseconds
: time-of-flight
''
: channel (dimensionless)center_errors: (required) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_ANY}
Uncentrainties on center in cUnit units.
@units: (required) NX_CHAR
Specify the *cUnit* units (see :ref:`center_type
Specify the cUnit units (see center_type)
Any of these values:
degrees
: two-theta
keV
: energy
1/angstrom
: momentum-transfer
angstrom
: d-spacing
microseconds
: time-of-flight
''
: channel (dimensionless)center_type: (required) NX_CHAR
The space in which :ref:`center ` is d ...
The space in which center is defined. It defines the cUnit as follows
if center_type=”two-theta” then cUnit must have the angle unit degrees
if center_type=”energy” then cUnit must have the energy unit keV
if center_type=”momentum-transfer” then cUnit must have the energy unit \(\unicode{x212B}^{-1}\)
if center_type=”d-spacing” then cUnit must have the energy unit \(\unicode{x212B}\)
if center_type=”channel” then cUnit must be dimensioness
if center_type=”time-of-flight” then cUnit must have the time-of-flight unit \(\mu\mathrm{s}\)
Any of these values:
two-theta
energy
momentum-transfer
d-spacing
channel
time-of-flight
sx: (required) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_LENGTH}
First component of the sample position in the sample reference frame. ...
First component of the sample position in the sample reference frame. The sample reference frame is defined by the sample transformations.
sy: (required) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_LENGTH}
First component of the sample position in the sample reference frame. ...
First component of the sample position in the sample reference frame. The sample reference frame is defined by the sample transformations.
sz: (required) NX_NUMBER (Rank: 1, Dimensions: [nPeaks]) {units=NX_LENGTH}
First component of the sample position in the sample reference frame. ...
First component of the sample position in the sample reference frame. The sample reference frame is defined by the sample transformations.
Hypertext Anchors¶
List of hypertext anchors for all groups, fields, attributes, and links defined in this class.
/NXstress/ENTRY/fit/background_parameters/background_area-field
/NXstress/ENTRY/fit/background_parameters/background_area@units-attribute
/NXstress/ENTRY/fit/background_parameters/background_area_interval-field
/NXstress/ENTRY/fit/DIFFRACTOGRAM/background@interpretation-attribute
/NXstress/ENTRY/fit/DIFFRACTOGRAM/diffractogram@interpretation-attribute
/NXstress/ENTRY/fit/DIFFRACTOGRAM/diffractogram@units-attribute
/NXstress/ENTRY/fit/DIFFRACTOGRAM/diffractogram_errors-field
/NXstress/ENTRY/fit/DIFFRACTOGRAM/diffractogram_errors@interpretation-attribute
/NXstress/ENTRY/fit/DIFFRACTOGRAM/diffractogram_errors@units-attribute
/NXstress/ENTRY/fit/DIFFRACTOGRAM/fit@interpretation-attribute
/NXstress/ENTRY/fit/DIFFRACTOGRAM/residuals@interpretation-attribute
/NXstress/ENTRY/fit/DIFFRACTOGRAM@auxiliary_signals-attribute
/NXstress/ENTRY/fit/peak_parameters/fwhm_left@units-attribute
/NXstress/ENTRY/fit/peak_parameters/fwhm_right@units-attribute
/NXstress/ENTRY/instrument/beam_intensity_profile/beam_evaluation-field
/NXstress/ENTRY/instrument/beam_intensity_profile/primary_horizontal_distance-field
/NXstress/ENTRY/instrument/beam_intensity_profile/primary_horizontal_evaluation-field
/NXstress/ENTRY/instrument/beam_intensity_profile/primary_horizontal_sample_width-field
/NXstress/ENTRY/instrument/beam_intensity_profile/primary_horizontal_source_width-field
/NXstress/ENTRY/instrument/beam_intensity_profile/primary_horizontal_type-field
/NXstress/ENTRY/instrument/beam_intensity_profile/primary_vertical_distance-field
/NXstress/ENTRY/instrument/beam_intensity_profile/primary_vertical_evaluation-field
/NXstress/ENTRY/instrument/beam_intensity_profile/primary_vertical_sample_width-field
/NXstress/ENTRY/instrument/beam_intensity_profile/primary_vertical_source_width-field
/NXstress/ENTRY/instrument/beam_intensity_profile/primary_vertical_type-field
/NXstress/ENTRY/instrument/beam_intensity_profile/secondary_horizontal_detector_width-field
/NXstress/ENTRY/instrument/beam_intensity_profile/secondary_horizontal_distance-field
/NXstress/ENTRY/instrument/beam_intensity_profile/secondary_horizontal_evaluation-field
/NXstress/ENTRY/instrument/beam_intensity_profile/secondary_horizontal_sample_width-field
/NXstress/ENTRY/instrument/beam_intensity_profile/secondary_horizontal_type-field
/NXstress/ENTRY/instrument/CALIBRATION/calibration_type-field
/NXstress/ENTRY/sample_description/gauge_volume/depends_on-field
/NXstress/ENTRY/sample_description/stress_field@direction-attribute