NXdelocalization¶
Status:
base class, extends NXobject
Description:
Base class to describe the delocalization of point-like objects on a grid.
Such a procedure is for instance used in image processing and e.g. atom probe microscopy (APM) to discretize a point cloud onto a grid to enable e.g. computing of point density, composition, or concentration values, obtain 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_isotopes: Number of isotopes in the whitelist.
- Groups cited:
none
Structure:
grid: (optional) NX_CHAR
Reference or link to the grid on which the delocalization is applied.
objects: (optional) NX_CHAR
Reference or link to the points which are delocalized on the grid.
weighting_model: (optional) NX_CHAR
The weighting model specifies how mark data are mapped to a weight per point. For atom probe microscopy (APM) as an example, different models are used which account differently for the multiplicity of an ion/atom:
default, points all get the same weight 1.; for APM this is equivalent to ion species
atomic_decomposition, points get as much weight as they have atoms of a type in element_whitelist,
isotope_decomposition, points get as much weight as they have isotopes of a type in isotope_whitelist.
This description shows an example that could be reinterpreted for similar such data processing steps in other fields of science.
Any of these values:
default
atomic_decomposition
isotope_decompositionelement_whitelist: (optional) NX_UINT (Rank: 1, Dimensions: [n_atoms]) {units=NX_UNITLESS}
A list of elements (via proton number) to consider for the atomic_decomposition weighting model. Elements must exist in the periodic table of elements.
isotope_whitelist: (optional) NX_UINT (Rank: 2, Dimensions: [n_isotopes, 2]) {units=NX_UNITLESS}
A list of isotopes to consider for the isotope_decomposition weighting model. Isotopes must exist in the nuclid table. Entries in the fastest changing dimension should be the pair of proton (first entry) and neutron number (second entry).
mark: (optional) NX_NUMBER (Rank: 2, Dimensions: [n_p, n_m])
Attribute data for each member of the point cloud. For APM these are the ion species labels generated via ranging. The number of mark data per point is 1 in the case for atom probe.
weight: (optional) NX_NUMBER
Weighting factor with which the integrated intensity per grid cell is multiplied specifically for each point. For APM the weight are positive integer values, specifically the multiplicity of the ion, according to the details of the weighting_model.
Hypertext Anchors¶
List of hypertext anchors for all groups, fields, attributes, and links defined in this class.
