Package org.jblas

Class Geometry

  • public class Geometry
extends java.lang.Object

    General functions which are geometric in nature.

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

    • 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).

      • 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).