NXspatial_filter

Status:

base class, extends NXobject

Description:

Spatial filter to filter entries within a region-of-interest based on their position.

Symbols:

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

n_ellipsoids: Number of ellipsoids.

n_hexahedra: Number of hexahedra.

n_cylinders: Number of cylinders.

Groups cited:

NXcg_cylinder_set, NXcg_ellipsoid_set, NXcg_hexahedron_set, NXcs_filter_boolean_mask

Structure:

windowing_method: (optional) NX_CHAR

Qualitative statement which specifies which spatial filtering with respective geometric primitives or bitmask is used. These settings are possible:

  • entire_dataset, no filter is applied, the entire dataset is used.

  • union_of_primitives, a filter with (rotated) geometric primitives. All ions in or on the surface of the primitives are considered while all other ions are ignored.

  • bitmasked_points, a boolean array whose bits encode with 1 which ions should be included. Those ions whose bit is set to 0 will be excluded. Users of python can use the bitfield operations of the numpy package to define such bitfields.

Conditions: In the case that windowing_method is entire_dataset all entries are processed. In the case that windowing_method is union_of_primitives, it is possible to specify none or all types of primitives (ellipsoids, cylinder, hexahedra). If no primitives are specified the filter falls back to entire_dataset. In the case that windowing_method is bitmask, the bitmask has to be defined; otherwise the filter falls back to entire dataset.

Any of these values: entire_dataset | union_of_primitives | bitmask

CG_ELLIPSOID_SET: (optional) NXcg_ellipsoid_set

CG_CYLINDER_SET: (optional) NXcg_cylinder_set

CG_HEXAHEDRON_SET: (optional) NXcg_hexahedron_set

CS_FILTER_BOOLEAN_MASK: (optional) NXcs_filter_boolean_mask

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/NXspatial_filter.nxdl.xml