Explore 3-D neutron histograms

Open a Mantid MDHistoWorkspace written by SaveMD, or any NeXus/HDF5 file whose NXdata group holds a 3-D histogram.

The example compares one crystal at 300 K and 10 K: short-range order above the transition, long-range order below.

Orthogonal slicesHK, HL and KL cuts in the true lattice geometry, linked by clicking.
Symmetry averagingAny Laue class or your own operations, pooled exactly on the bin grid.
Artifact maskingRemove detector-edge voxels and symmetry outliers before averaging.
3-D viewTransparent isosurface with the current slices as planes.

Or drop a file anywhere. Everything runs in your browser; the file is never uploaded.

Opening file

Starting…

Compare two datasetsoff

Colormap

Range

Scale

Softening

View ±

Guides where the other slices cut Nominal cell angles (60/90/120°)

Measured voxels—
Maskoff
Symmetry averagenone
Views3 slices + 3-D
NEBULA3D · 3D-ΔPDFnext analysis: export the volume

Symmetry averagingnone

Averages each voxel with its symmetry-equivalent voxels.

Laue class

Generators

Group operations (1)

Maskoff

Drops bad voxels (detector edges, outliers) before averaging.

Edge erosion Outlier cut k·σ

No mask: all measured voxels are used.

Show removed voxels

NEBULA3D · 3D-ΔPDFready

The last step here: hand the masked, symmetrized volume to NEBULA3D for 3D-ΔPDF analysis, in a new tab or as a file.

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Dataset

Method User guide Method Development

Slices

Each pixel is the equal-weight mean of the unique finite, unmasked voxels in the slab, pooled with all their symmetry equivalents. No smoothing or interpolation; grey means no measured contribution.

Symmetry

Generators are closed into a group, and every operation must map bin centers onto bin centers. A warning appears when the operations change the cell metric by more than 2%. Oblique axes use the reciprocal metric from the UB matrix.

Mask

Edge erosion removes measured voxels near unmeasured ones, where detector edges leave spurious values; the outlier cut removes voxels far above the median of their equivalents (1.4826·MAD). The mask acts before averaging.

3-D view

The volume is binned by an odd factor with blocks aligned to the origin, symmetrized and masked the same way, and drawn as a transparent isosurface with the current slices as planes.