2.3.3.3.99. NXdelocalization

Status:

base class, extends NXobject

Description:

Base class of the configuration and results of a delocalization algorithm. ...

Base class of the configuration and results of a delocalization algorithm.

Delocalization is used to distribute point-like objects on a grid to obtain e.g. smoother count, composition, or concentration values of scalar fields and compute gradients of these fields.

Symbols:

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

n_p: Number of points/objects.

n_m: Number of mark data per point/object.

n_atoms: Number of atoms in the whitelist.

n_nuclides: Number of isotopes in the whitelist.

Groups cited:

NXcg_grid, NXmatch_filter

Structure:

grid: (optional) NXcg_grid

Details about the grid on which the delocalization is applied.

weighting_model: (optional) NXmatch_filter

The weighting model specifies how mark data are mapped to a weight per ...

The weighting model specifies how mark data are mapped to a weight per point/object.

weighting_method: (optional) NX_CHAR

As an example from the research field of atom probe points/objects are (mole ...

As an example from the research field of atom probe points/objects are (molecular) ions. Different methods are used for weighting ions:

  • default, points get all the same weight 1., which for atom probe is equivalent

    to (molecular) iontype-based delocalization.

  • element, points get as much weight as they have atoms representing a nuclide with a proton number that is matching to a respective entry in whitelist. In atom probe jargon, this means atomic_decomposition.

  • isotope, points get as much weight as they have atoms representing a nuclides from a respective entry in whitelist. In atom probe jargon, this means isotope_decomposition.

Any of these values: default | element | isotope

method: (optional) NX_CHAR

Obligatory value: whitelist

match: (optional) NX_UINT (Rank: 1, Dimensions: [n_nuclides]) {units=NX_UNITLESS}

A list of nuclides based on which to evaluate the weight. Nuclides need to e ...

A list of nuclides based on which to evaluate the weight. Nuclides need to exist in the nuclide table. Values are nuclide (isotope) hash values using the following hashing rule \(H = Z + N \cdot 256\) with \(Z\) the number of protons and \(N\) the number of neutrons of the nuclide. For elements set \(N\) to zero.

mark: (optional) NX_NUMBER (Rank: 2, Dimensions: [n_p, n_m]) {units=NX_UNITLESS}

Attribute data for each member of the point cloud. For APM these are the ...

Attribute data for each member of the point cloud. For APM these are the iontypes generated via ranging. The number of mark data per point is 1 in the case for atom probe.

weight: (optional) NX_NUMBER (Rank: 1, Dimensions: [n_p]) {units=NX_UNITLESS}

Weighting factor with which the integrated intensity per grid cell is ...

Weighting factor with which the integrated intensity per grid cell is multiplied specifically for each point/object. For APM the weight are positive integer values, specifically the multiplicity of the ion, according to the details of the weighting_method.

Hypertext Anchors

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

NXDL Source:

https://github.com/FAIRmat-NFDI/nexus_definitions/tree/fairmat/contributed_definitions/NXdelocalization.nxdl.xml