org.apache.ignite.ml.math

Class Blas

java.lang.Object

org.apache.ignite.ml.math.Blas

public class Blas
extends Object

Useful subset of BLAS operations. This class is based on 'BLAS' class from Apache Spark MLlib.

Constructor Summary

Constructors

Constructor and Description
Blas()

Method Summary

Modifier and Type	Method and Description
static void	axpy(Double a, Vector x, Vector y) Performs y += a * x
static void	checkCardinality(Matrix a, Vector v) Checks if Matrix A can be multiplied by vector v, if not CardinalityException is thrown.
void	copy(Vector x, Vector y) Copies Vector x into Vector y.
static Double	dot(Vector x, Vector y) Returns dot product of vectors x and y.
static void	gemm(double alpha, Matrix a, Matrix b, double beta, Matrix c) For the moment we have no flags indicating if matrix is transposed or not.
static void	gemv(double alpha, Matrix a, Vector x, double beta, Vector y) y := alpha * A * x + beta * y.
static void	scal(Double a, Vector x) Performs in-place multiplication of vector x by a real scalar a.
static void	spr(Double alpha, DenseVector v, DenseVector u) Adds alpha * v * v.t to a matrix in-place.
static void	spr(Double alpha, SparseVector v, DenseVector u)
static void	syr(Double alpha, SparseVector x, DenseMatrix a)

Methods inherited from class java.lang.Object

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

Constructor Detail

Blas

public Blas()

Method Detail

axpy

public static void axpy(Double a,
                        Vector x,
                        Vector y)

Performs y += a * x

Parameters:

a - Scalar a.

x - Vector x.

y - Vector y.

dot

public static Double dot(Vector x,
                         Vector y)

Returns dot product of vectors x and y.

Parameters:

x - Vector x.

y - Vector y.

Returns:

Dot product of x and y.

copy

public void copy(Vector x,
                 Vector y)

Copies Vector x into Vector y. (y = x)

Parameters:

x - Vector x.

y - Vector y.

scal

public static void scal(Double a,
                        Vector x)

Performs in-place multiplication of vector x by a real scalar a. (x = a * x)

Parameters:

a - Scalar a.

x - Vector x.

spr

public static void spr(Double alpha,
                       DenseVector v,
                       DenseVector u)

Adds alpha * v * v.t to a matrix in-place. This is the same as BLAS's ?SPR.

Parameters:

u - the upper triangular part of the matrix in a [[DenseVector]](column major)

spr

public static void spr(Double alpha,
                       SparseVector v,
                       DenseVector u)

syr

public static void syr(Double alpha,
                       SparseVector x,
                       DenseMatrix a)

gemm

public static void gemm(double alpha,
                        Matrix a,
                        Matrix b,
                        double beta,
                        Matrix c)

For the moment we have no flags indicating if matrix is transposed or not. Therefore all dgemm parameters for transposition are equal to 'N'.

gemv

public static void gemv(double alpha,
                        Matrix a,
                        Vector x,
                        double beta,
                        Vector y)

y := alpha * A * x + beta * y.

Parameters:

alpha - Alpha.

a - Matrix a.

x - Vector x.

beta - Beta.

y - Vector y.

checkCardinality

public static void checkCardinality(Matrix a,
                                    Vector v)
                             throws CardinalityException

Checks if Matrix A can be multiplied by vector v, if not CardinalityException is thrown.

Parameters:

a - Matrix A.

v - Vector v.

Throws:

CardinalityException