```{index} single: Filters; Compute C-Axis Locations
```
# Compute C-Axis Locations

## Group (Subgroup)

Statistics (Crystallographic)

## Description

This **Filter** determines the direction <u,v,w> of the C-axis for each **Element** by applying the quaternion of the **Element** to the <001> direction, which is the C-axis for *Hexagonal* materials.  This will tell where the C-axis of the **Element** sits in the *sample reference frame*.

*Note:* This **Filter** will only work properly for *Hexagonal* materials.  The **Filter** does not apply any symmetry operators because there is only one c-axis (<001>) in *Hexagonal* materials and thus all symmetry operators will leave the c-axis in the same position in the sample *reference frame*.  However, in *Cubic* materials, for example, the {100} family of directions are all equivalent and the <001> direction will change location in the *sample reference frame* when symmetry operators are applied.


### Input Cell Data

| Parameter Name | Parameter Type | Parameter Notes | Description |
|----------------|----------------|-----------------|-------------|
| Cell Quaternions | Array Selection | Allowed Types: float32 Comp. Shape: 4 | DataPath to input quaternion values |
| Cell Phases | Array Selection | Allowed Types: int32 Comp. Shape: 1 | Specifies to which Ensemble each Cell belongs |

### Input Ensemble Data

| Parameter Name | Parameter Type | Parameter Notes | Description |
|----------------|----------------|-----------------|-------------|
| Crystal Structures | Array Selection | Allowed Types: uint32 Comp. Shape: 1 | Enumeration representing the crystal structure for each Ensemble |

### Output Cell Data

| Parameter Name | Parameter Type | Parameter Notes | Description |
|----------------|----------------|-----------------|-------------|
| C-Axis Locations | DataObjectName |  | DataPath to calculated C-Axis locations |

## Example Pipelines

EBSD_Hexagonal_Data_Analysis

## License & Copyright

Please see the description file distributed with this **Plugin**

## DREAM3D-NX Help

If you need help, need to file a bug report or want to request a new feature, please head over to the [DREAM3DNX-Issues](https://github.com/BlueQuartzSoftware/DREAM3DNX-Issues/discussions) GitHub site where the community of DREAM3D-NX users can help answer your questions.