```{image} ../../src/orangecontrib/ewoks3dxrd/icons/rings-smallest.svg
:alt: Index Filter Widget Icon
:class: widget-title-icon
```

# Index Filter Widget

The Index Filter widget provides a graphical interface to 
sub-select diffraction peaks based on their alignment with specific ring numbers. 
This step is critical for preparing data for the Grain Indexer, as it allows you to isolate peaks 
that correspond to known crystallographic planes of your phase.

## Functionality
This widget allows you to:
1. **Visualize Peak Distribution:** View all incoming peaks in a Reciprocal Distance ($ds​$) vs. Intensity plot.
2. **Overlay Theoretical Rings:** Automatically calculate and plot expected ring positions based on your lattice parameters.
3. **Select Active Rings:** Choose which specific rings should be used to filter the data for subsequent indexing.
4. **Inspect Logs:** View the internal ImageD11 output to verify ring assignments.


## User Interface
![Image showing the initial state of the Indexer Filtering widget](../_static/tuto/initial_index_filtering.png)

## Execution Control

```{include} ./execution_filtering.md
```

## Indexer Log Tab

A read-only text area displaying the captured standard output from ImageD11. 
This is useful for debugging ring identification and 
seeing exactly how many peaks were assigned to each hkl plane.

## Example Usage
1. Connect the widget to an Intensity Filter output or browse from your folder and select either geometry, lattice or intensity filtered data group.
2. Ensure the Lattice File and Wavelength (of the beam) are correctly populated from previous nodes.
3. Observe the plot; adjust $ds$​ Reciprocal distance tolerance if the theoretical rings do not align perfectly with the peak clusters.
4. Select the desired Ring Indices (e.g., 0, 1, 2) for the grains you wish to index.
5. Click Filter Peaks and verify the result in the plot as well as Indexer Log tab before proceeding to the Indexer widgets.

![Image showing the initial state of the index filtering widget](../_static/tuto/index_filtering.png)