9.134. Silhouette
Group (Subgroup)
DREAM3D Review (Clustering)
Description
This Filter computes the silhouette for a clustered Attribute Array. The user must select both the original array that has been clustered and the array of cluster Ids. The silhouette represents a measure for the quality of a clustering. Specifically, the silhouette provides a measure for how strongly a given point belongs to its own cluster compared to all other clusters. The silhouette is computed as follows:
\f[ s_{i} = \frac{b_{i} - a_{i}}{\max{a_{i},b_{i}}} \f]
where \f$ a \f$ is the average distance between point \f$ i \f$ and all other points in the cluster point \f$ i \f$ belongs to, \f$ b \f$ is the next closest average distance among all other clusters, and \f$ s \f$ is the silhouette value. Using this definition, \f$ s \f$ exists on the interval \f$ [-1, 1] \f$, where 1 indicates that the point strongly belongs to its current cluster and -1 indicates that the point does not belong well to its current cluster. The user may select from a variety of options to use as the distance metric. Additionally, the user may opt to use a mask array to ignore points in the silhouette; these points will contain a silhouette value of 0.
The silhouette can be used to determine how well a particular clustering has performed, such as k means or k medoids.
Input Parameter(s)
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Distance Metric |
Choices |
Distance Metric type to be used for calculations |
Optional Data Mask
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Use Mask Array |
Bool |
Specifies whether or not to use a mask array |
|
Mask Array |
Array Selection |
Allowed Types: uint8, boolean |
DataPath to the boolean or uint8 mask array. Values that are true will mark that cell/point as usable. |
Input Cell Data
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Attribute Array to Silhouette |
Array Selection |
Allowed Types: int8, uint8, int16, uint16, int32, uint32, int64, uint64, float32, float64 |
The DataPath to the input DataArray |
Cluster Ids |
Array Selection |
Allowed Types: int32 |
The DataPath to the DataArray that specifies which cluster each point belongs |
Output Cell Data
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Silhouette |
ArrayCreation |
The DataPath to the calculated output Silhouette array values |
Example Pipelines
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 GitHub site where the community of DREAM3D-NX users can help answer your questions.