NXorientation_set

Status:

base class, extends NXobject

Description:

Details about individual orientations of a set of objects.

For a more detailed insight into the discussion of parameterizing orientations in materials science see:

Symbols:

The symbols used in the schema to specify e.g. dimensions of arrays.

d: The dimensionality of the reference space/coordinate system.

c: The cardinality of the set, i.e. the number of orientations.

n_p: Number of parameters for the chosen parameterization.

Groups cited:

NXtransformations

Structure:

parameterization: (optional) NX_CHAR

Any of these values: bunge-euler (ZXZ) | quaternion

objects: (optional) NX_CHAR

A link or reference to the objects whose identifier are referred to in identifier to resolve which row tuple is the orientation of each object by reading orientations.

identifier_offset: (optional) NX_INT {units=NX_UNITLESS}

Integer which specifies which orientation (row of array orientation) matches to which object.e first index to be used for distinguishing hexahedra. Identifiers are defined either implicitly or explicitly. For implicit indexing the identifiers are defined on the interval [identifier_offset, identifier_offset+c-1]. For explicit indexing the identifier array has to be defined.

The identifier_offset field can for example be used to communicate if the identifiers are expected to start from 1 (referred to as Fortran-/Matlab-) or from 0 (referred to as C-, Python-style index notation) respectively.

identifier: (optional) NX_INT (Rank: 1, Dimensions: [c]) {units=NX_UNITLESS}

Integer used to distinguish how a row in orientation describes a specific object with an explicit identifier that can be queried via inspecting the list of available objects in objects.

The rational behind having such a more complicated pattern is that not all objects referred when following the link in objects may still exists or are still tracked when the orientation set was characterized.

This design enables to also use NXorientation_set in situations where the orientation of objects change as a function in time.

orientation: (optional) NX_NUMBER (Rank: 2, Dimensions: [c, n_p]) {units=NX_ANY}

Parameterized orientations.

TRANSFORMATIONS: (optional) NXtransformations

Reference to or definition of a coordinate system with which the definitions are interpretable.

Hypertext Anchors

List of hypertext anchors for all groups, fields, attributes, and links defined in this class.

NXDL Source:

https://github.com/FAIRmat-Experimental/nexus_definitions/tree/fairmat/contributed_definitions/NXorientation_set.nxdl.xml