Grain Plot#

../_images/grainplot.png

Widget to compute, display and export moments of the grain.

This widget can display the following grain maps:

  • Center of mass (COM): Shows the map of COM for every motor. The center of mass looks at the intensity as a function of a motor position, using the intensity values of the images as a statistical weight

  • Full width half maximum (FWHM): Same as COM but with the standard deviation

  • Skewness, Kurtosis: third and fourth-order computed standardized moments

There is also a dedicate tab to the mosaicity and the orientation distribution for 2D and 3D scans.

Hint

Have a look an the Mosaicity tab tutorial below for more explanations about mosaicity tab.

Mosaicity tab tutorial#

This tutorial is dedicated to the mosaicity tab.

The Mosaicity tab is organized around two complementary plots:

  • Mosaicity A 2D view of the center‑of‑mass (CoM)

  • Orentation distribution 2D heat-map. Obtained from weighted 2D histogram based on Center of Mass of the first and the second dimension and ZSum of the detector data as the weight.

Note

Several new features are available since 4.1 version

Plots Common Toolbars.#

../_images/toolbar.png

Interactive toolbar

First toolbar contains three tools zoom, pan and flashlight.

This toolbar is available from both the mosaicity (left) and the Orientation Distribution (right) plots.

  • zoom and pan are casual actions available in any plot widget.

  • flashlight is a new interactive action that lets the user defining a rectangular Region Of Interest (ROI) that follows the mouse cursor. * ROI can be resized by maintaining left button pressed. * ROI center and size is shown below the selection. The flashlight selection from the right plot illuminate the corresponding range of values in the left plot. The same mapping is done from the left plot to the right plot.

../_images/flashlight.gif

Common utils toolbar

Second toolbar ; accessible from both plots ; contains four tools relative to data saving, export and aspect ratio.

  • copy: Take a screenshot of the plot and place it on the system clipboard.

  • save: Save the plot. Different format available.

    Note

    this is different from the export maps button because this only save the content of one plot.

  • print : Similar to save.

    Warning

    An exception occurs with last version of silx dependencies ! (Need to be fixed)

  • aspect ratio: Enable or disable the Keep aspect ratio option, which forces the plot’s X‑ and Y‑axes to maintain a fixed proportional scaling (e.g., 1 : 1).

Orientation distribution configuration toolbar

Third toolbar is specific to the right plot.

The Orientation distribution data is a heat-map (2D - histogram) of the Center of Mass values.

Note

This view is only available for dataset at least 2D.

Contours are drawn to reveal area of the distribution with the highest intensity value.

  • Normalization Data colormap and contours normalization (linear or log).

  • Axis allow to select horizontal and vertical axis representation. Default are the motor coordinates. Options are move origin to 0 (Substract min motor coordinate) and centered (Substract (min + max) / 2).

  • Color key tool This tool allow user to adjust the blend between data intensity layer and HSV key layer.

    If checked, Orientation Distribution only shows a HSV layer relative to X and Y dimension.

    To determine intensity of an area of the plot you can use the contours.

    Area with zero intensity values have a lower brightness. You can play with the slider of the tool to change this brightness.

    ../_images/tune_key.gif

    If unchecked, Orientation Distribution show the two layers: Data intensity as an alpha layer and HSV key as a background layer.

    The visibility of the Data intensity layer can be tuned from the slider.

    ../_images/tune_data.gif

  • Contour tool This tool allow user to configure contours. Can be unchecked (No contours) and a slider can be use to define the number of contours.

  • Median Filter Whether a media filter should be applied on the data. Note that contours are always base on a median filter of the data (no matter this option).

Threshold and range#

../_images/threshold_and_range.png

Threshold spinbox allow user to discard values above a certain threshold in the ZSum. These values will be shown as black in the mosaicity and less darker in the orientation distribution plot (Depending on Color key tool tuning).

The two range sliders allow to fix manually a axis range in the orientation distribution. Values outside this range in the mosaicity plot are shown with a dark grey color.