Base class inheritance example

base_classes/nyaml/NXbeam.yaml

@@ -0,0 +1,218 @@
+doc: | 
+  Properties of a beam of radiation or matter at a given location.
+
+  This group is intended to be referenced
+  by beamline component groups within the :ref:`NXinstrument` group or by the :ref:`NXsample` group. This group is
+  especially valuable in storing the results of instrument simulations in which it is useful
+  to specify the beam profile, time distribution etc. at each beamline component. Otherwise,
+  its most likely use is in the :ref:`NXsample` group in which it defines the results of the neutron
+  scattering by the sample, e.g., energy transfer, polarizations. Finally, There are cases where the beam is
+  considered as a beamline component and this group may be defined as a subgroup directly inside
+  :ref:`NXinstrument`, in which case it is recommended that the position of the beam is specified by an
+  :ref:`NXtransformations` group, unless the beam is at the origin (which is the sample).
+
+  Note that incident_wavelength and related fields can be a scalar values or arrays, depending on the use case.
+  To support these use cases, the explicit dimensionality of these fields is not specified, but it can be inferred
+  by the presense of and shape of accompanying fields, such as incident_wavelength_weights for a polychromatic beam.
+symbols: 
+    doc: |
+      These symbols coordinate datasets with the same shape.
+
+    nP: |
+      Number of scan points.
+
+    m: |
+      Number of channels in the incident beam spectrum, if known
+
+    c: |
+      Number of moments representing beam divergence (x, y, xy, etc.)
+
+category: base
+NXbeam:
+  distance(NX_FLOAT):
+    unit: NX_LENGTH
+    doc: |
+      Distance from sample. Note, it is recommended to use NXtransformations instead.
+  energy(NX_FLOAT):
+    unit: NX_ENERGY
+    doc: |
+      Energy carried by each particle of the beam at the given location.
+
+      In the case of a monochromatic beam this is the scalar energy.
+      Several other use cases are permitted, depending on the
+      presence of other incident_energy_X fields.
+
+      * In the case of a polychromatic beam this is an array of length m of energies, with the relative weights in incident_energy_weights.
+      * In the case of a monochromatic beam that varies shot-to-shot, this is an array of energies, one for each recorded shot.
+      Here, incident_energy_weights and incident_energy_spread are not set.
+      * In the case of a polychromatic beam that varies shot-to-shot,
+      this is an array of length m with the relative weights in incident_energy_weights as a 2D array.
+      * In the case of a polychromatic beam that varies shot-to-shot and where the channels also vary,
+      this is a 2D array of dimensions nP by m (slow to fast) with the relative weights in incident_energy_weights as a 2D array.
+
+      Note, variants are a good way to represent several of these use cases in a single dataset,
+      e.g. if a calibrated, single-value energy value is available along with the original spectrum from which it was calibrated.
+    dim: (m,)
+  energy_spread(NX_NUMBER):
+    unit: NX_ENERGY
+    doc: |
+      The energy spread FWHM for the corresponding energy(ies) in energy. In the case of shot-to-shot variation in
+      the energy spread, this is a 2D array of dimension nP by m
+      (slow to fast) of the spreads of the corresponding
+      wavelength in incident_wavelength.
+  energy_weights(NX_NUMBER):
+    unit: NX_ENERGY
+    doc: |
+      In the case of a polychromatic beam this is an array of length m of the relative
+      weights of the corresponding energies in energy. In the case of a
+      polychromatic beam that varies shot-to-shot, this is a 2D array of dimensions np
+      by m (slow to fast) of the relative weights of the corresponding energies in
+      incident_energy.
+  energy_transfer(NX_FLOAT):
+    unit: NX_ENERGY
+    doc: |
+      Change in particle energy caused by the beamline component
+    dim: (m,)
+  wavelength(NX_FLOAT):
+    unit: NX_WAVELENGTH
+    doc: |
+      In the case of a monochromatic beam this is the scalar
+      wavelength.
+
+      Several other use cases are permitted, depending on the
+      presence or absence of other incident_wavelength_X
+      fields.
+
+      In the case of a polychromatic beam this is an array of
+      length **m** of wavelengths, with the relative weights
+      in ``incident_wavelength_weights``.
+
+      In the case of a monochromatic beam that varies shot-
+      to-shot, this is an array of wavelengths, one for each
+      recorded shot. Here, ``incident_wavelength_weights`` and
+      incident_wavelength_spread are not set.
+
+      In the case of a polychromatic beam that varies shot-to-
+      shot, this is an array of length **m** with the relative
+      weights in ``incident_wavelength_weights`` as a 2D array.
+
+      In the case of a polychromatic beam that varies shot-to-
+      shot and where the channels also vary, this is a 2D array
+      of dimensions **nP** by **m** (slow to fast) with the
+      relative weights in ``incident_wavelength_weights`` as a 2D
+      array.
+
+      Note, :ref:`variants <Design-Variants>` are a good way
+      to represent several of these use cases in a single dataset,
+      e.g. if a calibrated, single-value wavelength value is
+      available along with the original spectrum from which it
+      was calibrated.
+      Wavelength on entering beamline component
+  wavelength_weights(NX_FLOAT):
+    doc: |
+      In the case of a polychromatic beam this is an array of
+      length **m** of the relative weights of the corresponding
+      wavelengths in ``wavelength``.
+
+      In the case of a polychromatic beam that varies shot-to-
+      shot, this is a 2D array of dimensions **nP** by **m**
+      (slow to fast) of the relative weights of the
+      corresponding wavelengths in ``incident_wavelength``.
+  wavelength_spread(NX_FLOAT):
+    unit: NX_WAVELENGTH
+    doc: |
+      The wavelength spread FWHM for the corresponding
+      wavelength(s) in wavelength.
+
+      In the case of shot-to-shot variation in the wavelength
+      spread, this is a 2D array of dimension **nP** by
+      **m** (slow to fast) of the spreads of the
+      corresponding wavelengths in incident_wavelength.
+    dim: (nP,)
+  beam_divergence(NX_FLOAT):
+    unit: NX_ANGLE
+    doc: |
+      Beam crossfire in degrees parallel to the laboratory X axis
+
+      The dimension **c** is a series of moments of that represent
+      the standard uncertainty (e.s.d.) of the directions of
+      of the beam. The first and second moments are in the XZ and YZ
+      planes around the mean source beam direction, respectively.
+
+      Further moments in **c** characterize co-variance terms, so
+      the next moment is the product of the first two, and so on.
+    dim: (nP, c)
+  extent(NX_FLOAT):
+    unit: NX_LENGTH
+    doc: |
+      Size of the beam entering this component. Note this represents
+      a rectangular beam aperture, and values represent FWHM
+    dim: (nP, 2)
+  flux(NX_FLOAT):
+    unit: NX_FLUX
+    doc: |
+      Flux incident on beam plane area
+    dim: (nP,)
+  (NXdata):
+    doc: |
+      Distribution of beam with respect to relevant variable e.g. wavelength. This is mainly
+      useful for simulations which need to store plottable information at each beamline
+      component.
+  \@default:
+    doc: |
+      .. index:: plotting
+
+      Declares which child group contains a path leading
+      to a :ref:`NXdata` group.
+
+      It is recommended (as of NIAC2014) to use this attribute
+      to help define the path to the default dataset to be plotted.
+      See https://www.nexusformat.org/2014_How_to_find_default_data.html
+      for a summary of the discussion.
+  depends_on(NX_CHAR):
+    doc: |
+      The NeXus coordinate system defines the Z axis to be along the nominal beam
+      direction. This is the same as the McStas coordinate system (see :ref:`Design-CoordinateSystem`).
+      However, the additional transformations needed to represent an altered beam
+      direction can be provided using this depends_on field that contains the path
+      to a NXtransformations group. This could represent redirection of the beam,
+      or a refined beam direction.
+  (NXtransformations):
+    doc: |
+      Direction (and location) for the beam. The location of the beam can be given by
+      any point which it passes through as its offset attribute.
+    DIRECTION(NX_NUMBER):
+      unit: NX_TRANSFORMATION
+      doc: |
+        Direction of beam vector, its value is ignored. If missing, then the beam direction is defined as [0,0,1]
+        and passes through the origin
+      \@transformation_type:
+        enumeration: [translation]
+      \@vector:
+        doc: |
+          Three values that define the direction of beam vector
+      \@offset:
+        doc: |
+          Three values that define the location of a point through which the beam passes
+      \@depends_on:
+        doc: |
+          Points to the path to a field defining the location on which this
+          depends or the string "." for origin.
+    reference_plane(NX_NUMBER):
+      unit: NX_TRANSFORMATION
+      doc: |
+        Direction of normal to reference plane used to measure azimuth relative to the beam, its value is ignored.
+        This also defines the parallel and perpendicular components of the beam's polarization.
+        If missing, then the reference plane normal is defined as [0,1,0] and passes through the origin
+      \@transformation_type:
+        enumeration: [translation]
+      \@vector:
+        doc: |
+          Three values that define the direction of reference plane normal
+      \@offset:
+        doc: |
+          Not required as beam direction offset locates the plane
+      \@depends_on:
+        doc: |
+          Points to the path to a field defining the location on which this
+          depends or the string "." for origin.

base_classes/nyaml/NXbeam_electron.yaml

@@ -0,0 +1,4 @@
+doc: |
+  Properties of an electron beam at a given location.
+category: base
+NXbeam_electron(NXbeam):

base_classes/nyaml/NXbeam_neutron.yaml

@@ -0,0 +1,4 @@
+doc: |
+  Properties of a neutron beam at a given location.
+category: base
+NXbeam_neutron(NXbeam):

base_classes/nyaml/NXbeam_optical.yaml

@@ -0,0 +1,4 @@
+doc: |
+  Properties of an optical beam at a given location.
+category: base
+NXbeam_optical(NXbeam):

base_classes/nyaml/NXbeam_polarized.yaml

@@ -0,0 +1,51 @@
+doc: |
+  Properties of an optical beam at a given location.
+category: base
+NXbeam_polarized(NXbeam):
+  polarization(NX_NUMBER):
+    unit: NX_ANY
+    doc: |
+      Polarization as a Stokes vector at the given location
+      of the beam.
+    dim: (nP, 2)
+    \@units:
+      doc: |
+        The units for this observable are not included in the NIAC list.
+        Responsibility on correct formatting and parsing is handed to the user
+        by using `NX_ANY`. Correct parsing can still be implemented by using
+        this attribute.
+
+        | Fill with:
+
+        * The unit unidata symbol if the unit has one (Example: T for the unit of magnetic flux density tesla).
+        * The unit unidata name if the unit has a name (Example: farad for capacitance).
+        * A string describing the units according to unidata unit operation notation, if the unit is a complex combination of named units and
+        does not have a name.
+
+        Example: for lightsource brilliance (SI) 1/(s.mm2.mrad2).
+        Here: SI units are V2/m2.
+  polarization_stokes(NX_NUMBER):
+    unit: NX_ANY
+    doc: |
+      Polarization vector at the given location of the beam using Stokes notation
+
+      The Stokes parameters are four components labelled I,Q,U,V or S_0,S_1,S_2,S_3.
+      These are defined with the standard Nexus coordinate frame unless it is
+      overridden by an NXtransformations field pointed to by a depends_on attribute.
+      The last component, describing the circular polarization state, is positive
+      for a right-hand circular state - that is the electric field vector rotates
+      clockwise at the sample and over time when observed from the source.
+
+      I (S_0) is the beam intensity (often normalized to 1). Q, U, and V scale
+      linearly with the total degree of polarization, and indicate the relative
+      magnitudes of the pure linear and circular orientation contributions.
+
+      Q (S_1) is linearly polarized along the x axis (Q > 0) or y axis (Q < 0).
+
+      U (S_2) is linearly polarized along the x==y axis (U > 0) or the
+      -x==y axis (U < 0).
+
+      V (S_3) is circularly polarized. V > 0 when the electric field vector rotates
+      clockwise at the sample with respect to time when observed from the source;
+      V < 0 indicates the opposite rotation.
+    dim: (nP, 4)

base_classes/nyaml/NXbeam_polarized_time_resolved.yaml

@@ -0,0 +1,4 @@
+doc: |
+  A polarized and time-resolved beam
+category: base
+NXbeam_polarized_time_resolved(NXbeam_polarized, NXbeam_time_resolved):

base_classes/nyaml/NXbeam_time_resolved.yaml

@@ -0,0 +1,52 @@
+doc: |
+  Properties of an optical time resolved beam at a given location.
+symbols:
+  nx: Number of x-axis points of the FROG trace
+  ny: Number of y-axis points of the FROG trace
+category: base
+NXbeam_time_resolved(NXbeam):
+  pulse_energy(NX_FLOAT):
+    unit: NX_ENERGY
+    doc: |
+      Energy of a single pulse at the diagnostic point
+  average_power(NX_FLOAT):
+    unit: NX_POWER
+    doc: |
+      Average power at the diagnostic point
+  fluence(NX_FLOAT):
+    unit: NX_ANY
+    doc: |
+      Incident fluence at the diagnostic point
+    \@units:
+      doc: |
+        Here: SI units are 'J/m2', customary 'mJ/cm2'.
+  pulse_duration(NX_FLOAT):
+    unit: NX_TIME
+    doc: |
+      FWHM duration of the pulses at the diagnostic point
+  frog_trace(NX_FLOAT):
+    doc: |
+      FROG trace of the pulse.
+    exists: optional
+    dim: (nx, ny)
+  frog_delays(NX_FLOAT):
+    unit: NX_TIME
+    doc: |
+      Horizontal axis of a FROG trace, i.e. delay.
+    exists: optional
+    dim: (nx,)
+  frog_frequencies(NX_FLOAT):
+    unit: NX_FREQUENCY
+    doc: |
+      Vertical axis of a FROG trace, i.e. frequency.
+    exists: optional
+    dim: (ny,)
+  chirp_type(NX_CHAR):
+    doc: |
+      The type of chirp implemented
+    exists: optional
+  chirp_GDD(NX_FLOAT):
+    unit: NX_TIME
+    doc: |
+      Group delay dispersion of the pulse for linear chirp
+    exists: optional

base_classes/nyaml/NXbeam_xray.yaml

@@ -0,0 +1,4 @@
+doc: |
+  Properties of an x-ray beam at a given location.
+category: base
+NXbeam_xray(NXbeam_optical):