2.3.3.3.152. NXms_ipf¶
Status:
base class, extends NXprocess
Description:
Base class to store an inverse pole figure (IPF) mapping (IPF map).
Symbols:
n_z: Number of pixel along the z slowest direction.
n_y: Number of pixel along the y slow direction.
n_x: Number of pixel along the x fast direction.
n_rgb: Number of RGB values along the fastest direction, always three.
d: Dimensionality of the mapping (either 2 or 3).
Structure:
@depends_on: (optional) NX_CHAR
Reference to the coordinate system whereby the projection_direction is defined ...
Reference to the coordinate system whereby the projection_direction is defined.
If the field depends_on is not provided but a parent of the instance of this base class or its specialization defines an NXcoordinate_system_set and exactly one NXcoordinate_system, the reference points to this system.
If nothing is provided and none of the above-mentioned references pointing in a parent, McStas is assumed.
projection_direction: (optional) NX_NUMBER (Rank: 1, Dimensions: [3]) {units=NX_UNITLESS}
The direction along which orientations are projected.
interpolation: (optional) NX_CHAR
How where orientation values at the location of the output grid ...
How where orientation values at the location of the output grid positions computed.
Nearest neighbour means the orientation of the closed (Euclidean distance) grid point of the input_grid was taken.
Obligatory value:
nearest_neighbourinput_grid: (optional) NXcg_grid
Details about the original grid. ...
Details about the original grid.
Here original grid means the one onto which the IPF map was computed when exported from the tech partner’s file format representation.
output_grid: (optional) NXcg_grid
Details about the grid onto which the IPF is recomputed. ...
Details about the grid onto which the IPF is recomputed.
Rescaling the visualization of the IPF map may be needed to enable visualization in specific software tools like H5Web. The value specifies the fractional change of the spacing between the original mapping and the scaled one.
map: (optional) NXdata
Inverse pole figure mapping. ...
Inverse pole figure mapping.
Default inverse pole figure (IPF) plot of the data specific for each phase. No ipf_mapID instances for non-indexed scan points as these are by definition assigned the null phase with phase_identifier 0. Inspect the definition of NXcrystal_structure and its field phase_identifier for further details.
Details about possible regridding and associated interpolation during the computation of the IPF map visualization can be stored using the input_grid, output_grid, and interpolation fields.
The main purpose of this map is to offer a normalized default representation of the IPF map for consumption by a research data management system (RDMS). This is aligned with the first aim of NXms_ipf, to bring colleagues and users of IPF maps together to discuss which pieces of information need to be stored together. We are convinced a step-by-step design and community-driven discussion about which pieces of information should and/or need to be included is a practical strategy to work towards an interoperable description and data model for exchanging IPF maps as specific community-accepted tools to convey orientation maps.
With this design the individual RDMS solutions and tools can still continue to support specific custom data analyses workflow and routes but at least there is one common understanding which enables also those users who are not necessarily experts in all the details of the underlying techniques can understand and thus eventually judge if the dataset is worth to be reused or repurposed.
data: (optional) NX_NUMBER (Rank: 3, Dimensions: [n_y, n_x, 3]) {units=NX_UNITLESS} ⤆
Inverse pole figure color code for each map coordinate.
axis_z: (optional) NX_NUMBER (Rank: 1, Dimensions: [n_z]) {units=NX_LENGTH} ⤆
Pixel center coordinate calibrated for step size along the z axis of the map.
axis_y: (optional) NX_NUMBER (Rank: 1, Dimensions: [n_y]) {units=NX_LENGTH} ⤆
Pixel center coordinate calibrated for step size along the y axis of the map.
axis_x: (optional) NX_NUMBER (Rank: 1, Dimensions: [n_x]) {units=NX_LENGTH} ⤆
Pixel center coordinate calibrated for step size along the x axis of the map.
legend: (optional) NXdata
The color code which maps colors into orientation into the fundamental zone. ...
The color code which maps colors into orientation into the fundamental zone.
For each stereographic standard triangle (SST), i.e. a rendering of the fundamental zone of the crystal-symmetry-reduced orientation space SO3, it is possible to define a color model which assigns each point in the fundamental zone a color.
Different mapping models are used. These implement (slightly) different scaling relations. Differences exist across representations of tech partners.
Differences are which base colors of the RGB color model are placed in which extremal position of the SST and where the white point is located.
For further details see:
[G. Nolze et al.](https://doi.org/10.1107/S1600576716012942)
Srikanth Patala and coworkers”’” work and of others.
Details are implementation-specific and not standardized yet.
Given that the SST has a complicated geometry, it cannot yet be visualized using tools like H5Web, which is why for now the matrix of a rasterized image which is rendered by the backend tool gets copied into an RGB matrix to offer a default plot.
data: (optional) NX_NUMBER (Rank: 3, Dimensions: [n_y, n_x, 3]) {units=NX_UNITLESS} ⤆
Inverse pole figure color code for each map coordinate.
axis_y: (optional) NX_NUMBER (Rank: 1, Dimensions: [n_y]) {units=NX_UNITLESS} ⤆
Pixel along the y-axis.
axis_x: (optional) NX_NUMBER (Rank: 1, Dimensions: [n_x]) {units=NX_UNITLESS} ⤆
Pixel along the x-axis.
Hypertext Anchors¶
List of hypertext anchors for all groups, fields, attributes, and links defined in this class.
