ML::Metrics::Batched Namespace Reference

Functions
float	silhouette_score (const raft::handle_t &handle, float *X, int n_rows, int n_cols, int *y, int n_labels, float *scores, int chunk, raft::distance::DistanceType metric)
double	silhouette_score (const raft::handle_t &handle, double *X, int n_rows, int n_cols, int *y, int n_labels, double *scores, int chunk, raft::distance::DistanceType metric)

Function Documentation

silhouette_score() [1/2]

double ML::Metrics::Batched::silhouette_score	(	const raft::handle_t &	handle,
		double *	X,
		int	n_rows,
		int	n_cols,
		int *	y,
		int	n_labels,
		double *	scores,
		int	chunk,
		raft::distance::DistanceType	metric
	)

silhouette_score() [2/2]

float ML::Metrics::Batched::silhouette_score	(	const raft::handle_t &	handle,
		float *	X,
		int	n_rows,
		int	n_cols,
		int *	y,
		int	n_labels,
		float *	scores,
		int	chunk,
		raft::distance::DistanceType	metric
	)

Calculates Batched "Silhouette Score" by tiling the pairwise distance matrix to remove use of quadratic memory

The Silhouette Coefficient is calculated using the mean intra-cluster distance (a) and the mean nearest-cluster distance (b) for each sample. The Silhouette Coefficient for a sample is (b - a) / max(a, b). To clarify, b is the distance between a sample and the nearest cluster that the sample is not a part of. Note that Silhouette Coefficient is only defined if number of labels is 2 <= n_labels <= n_samples - 1.

Parameters

[in]	handle	raft::handle_t
[in]	X	Array of data samples with dimensions (n_rows x n_cols)
[in]	n_rows	number of data samples
[in]	n_cols	number of features
[in]	y	Array containing labels for every data sample (1 x n_rows)
[in]	n_labels	number of Labels
[in]	metric	the numerical value that maps to the type of distance metric to be used in the calculations
[in]	chunk	the row-wise chunk size on which the pairwise distance matrix is tiled
[out]	scores	Array that is optionally taken in as input if required to be populated with the silhouette score for every sample (1 x nRows), else nullptr is passed