org.jblas

Class Geometry

java.lang.Object

org.jblas.Geometry

public class Geometry
extends Object

General functions which are geometric in nature.

For example, computing all pairwise squared distances between all columns of a matrix.

Constructor Summary

Constructors

Constructor and Description
Geometry()

Method Summary

Modifier and Type	Method and Description
static DoubleMatrix	center(DoubleMatrix x) Center a vector (subtract mean from all elements (in-place).
static FloatMatrix	center(FloatMatrix x) Center a vector (subtract mean from all elements (in-place).
static DoubleMatrix	centerColumns(DoubleMatrix x) Center the columns of a matrix (in-place).
static FloatMatrix	centerColumns(FloatMatrix x) Center the columns of a matrix (in-place).
static DoubleMatrix	centerRows(DoubleMatrix x) Center the rows of a matrix (in-place).
static FloatMatrix	centerRows(FloatMatrix x) Center the rows of a matrix (in-place).
static DoubleMatrix	normalize(DoubleMatrix x) Normalize a vector (scale such that its Euclidean norm is 1) (in-place).
static FloatMatrix	normalize(FloatMatrix x) Normalize a vector (scale such that its Euclidean norm is 1) (in-place).
static DoubleMatrix	normalizeColumns(DoubleMatrix x) Normalize the columns of a matrix (in-place).
static FloatMatrix	normalizeColumns(FloatMatrix x) Normalize the columns of a matrix (in-place).
static DoubleMatrix	normalizeRows(DoubleMatrix x) Normalize the rows of a matrix (in-place).
static FloatMatrix	normalizeRows(FloatMatrix x) Normalize the rows of a matrix (in-place).
static DoubleMatrix	pairwiseSquaredDistances(DoubleMatrix X, DoubleMatrix Y) Compute the pairwise squared distances between all columns of the two matrices.
static FloatMatrix	pairwiseSquaredDistances(FloatMatrix X, FloatMatrix Y) Compute the pairwise squared distances between all columns of the two matrices.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Geometry

public Geometry()

Method Detail

pairwiseSquaredDistances

public static DoubleMatrix pairwiseSquaredDistances(DoubleMatrix X,
                                                    DoubleMatrix Y)

Compute the pairwise squared distances between all columns of the two matrices.

An efficient way to do this is to observe that (x-y)^2 = x^2 - 2xy - y^2 and to then properly carry out the computation with matrices.

center

public static DoubleMatrix center(DoubleMatrix x)

Center a vector (subtract mean from all elements (in-place).

centerRows

public static DoubleMatrix centerRows(DoubleMatrix x)

Center the rows of a matrix (in-place).

centerColumns

public static DoubleMatrix centerColumns(DoubleMatrix x)

Center the columns of a matrix (in-place).

normalize

public static DoubleMatrix normalize(DoubleMatrix x)

Normalize a vector (scale such that its Euclidean norm is 1) (in-place).

normalizeRows

public static DoubleMatrix normalizeRows(DoubleMatrix x)

Normalize the rows of a matrix (in-place).

normalizeColumns

public static DoubleMatrix normalizeColumns(DoubleMatrix x)

Normalize the columns of a matrix (in-place).

pairwiseSquaredDistances

public static FloatMatrix pairwiseSquaredDistances(FloatMatrix X,
                                                   FloatMatrix Y)

Compute the pairwise squared distances between all columns of the two matrices.

An efficient way to do this is to observe that (x-y)^2 = x^2 - 2xy - y^2 and to then properly carry out the computation with matrices.

center

public static FloatMatrix center(FloatMatrix x)

Center a vector (subtract mean from all elements (in-place).

centerRows

public static FloatMatrix centerRows(FloatMatrix x)

Center the rows of a matrix (in-place).

centerColumns

public static FloatMatrix centerColumns(FloatMatrix x)

Center the columns of a matrix (in-place).

normalize

public static FloatMatrix normalize(FloatMatrix x)

Normalize a vector (scale such that its Euclidean norm is 1) (in-place).

normalizeRows

public static FloatMatrix normalizeRows(FloatMatrix x)

Normalize the rows of a matrix (in-place).

normalizeColumns

public static FloatMatrix normalizeColumns(FloatMatrix x)

Normalize the columns of a matrix (in-place).