Package org.jblas

Class JavaBlas

java.lang.Object

org.jblas.JavaBlas

public class JavaBlas
extends java.lang.Object

Implementation of some Blas functions, mostly those which require linear runtime in the number of matrix elements. Because of the copying overhead when passing primitive arrays to native code, it doesn't make sense for these functions to be implemented in native code. The Java code is about as fast.

The same conventions were used as in the native code, that is, for each array you also pass an index pointing to the starting index.

These methods are mostly optimized for the case where the starting index is 0 and the increment is 1.

Constructor Summary

Constructors

Constructor	Description
JavaBlas()

Method Summary

Modifier and Type	Method	Description
static void	raxpy(int n, double da, double[] dx, int dxIdx, int incx, double[] dy, int dyIdx, int incy)	Compute dy <- da * dx + dy.
static void	raxpy(int n, float da, float[] dx, int dxIdx, int incx, float[] dy, int dyIdx, int incy)	Compute dy <- da * dx + dy.
static void	rcopy(int n, double[] dx, int dxIdx, int incx, double[] dy, int dyIdx, int incy)	Copy dx to dy.
static void	rcopy(int n, float[] dx, int dxIdx, int incx, float[] dy, int dyIdx, int incy)	Copy dx to dy.
static double	rdot(int n, double[] dx, int dxIdx, int incx, double[] dy, int dyIdx, int incy)	Compute scalar product between dx and dy.
static float	rdot(int n, float[] dx, int dxIdx, int incx, float[] dy, int dyIdx, int incy)	Compute scalar product between dx and dy.
static void	rswap(int n, double[] dx, int dxIdx, int incx, double[] dy, int dyIdx, int incy)	Exchange two vectors.
static void	rswap(int n, float[] dx, int dxIdx, int incx, float[] dy, int dyIdx, int incy)	Exchange two vectors.
static void	rzaxpy(int n, double[] dz, int dzIdx, int incz, double da, double[] dx, int dxIdx, int incx, double[] dy, int dyIdx, int incy)	Computes dz <- dx + dy
static void	rzaxpy(int n, float[] dz, int dzIdx, int incz, float da, float[] dx, int dxIdx, int incx, float[] dy, int dyIdx, int incy)	Computes dz <- dx + dy
static void	rzgxpy(int n, double[] dz, double[] dx, double[] dy)
static void	rzgxpy(int n, float[] dz, float[] dx, float[] dy)

Methods inherited from class java.lang.Object

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

Constructor Detail

JavaBlas

public JavaBlas()

Method Detail

rswap

public static void rswap(int n,
                         double[] dx,
                         int dxIdx,
                         int incx,
                         double[] dy,
                         int dyIdx,
                         int incy)

Exchange two vectors.

rcopy

public static void rcopy(int n,
                         double[] dx,
                         int dxIdx,
                         int incx,
                         double[] dy,
                         int dyIdx,
                         int incy)

Copy dx to dy.

raxpy

public static void raxpy(int n,
                         double da,
                         double[] dx,
                         int dxIdx,
                         int incx,
                         double[] dy,
                         int dyIdx,
                         int incy)

Compute dy <- da * dx + dy.

rzaxpy

public static void rzaxpy(int n,
                          double[] dz,
                          int dzIdx,
                          int incz,
                          double da,
                          double[] dx,
                          int dxIdx,
                          int incx,
                          double[] dy,
                          int dyIdx,
                          int incy)

Computes dz <- dx + dy

rzgxpy

public static void rzgxpy(int n,
                          double[] dz,
                          double[] dx,
                          double[] dy)

rdot

public static double rdot(int n,
                          double[] dx,
                          int dxIdx,
                          int incx,
                          double[] dy,
                          int dyIdx,
                          int incy)

Compute scalar product between dx and dy.

rswap

public static void rswap(int n,
                         float[] dx,
                         int dxIdx,
                         int incx,
                         float[] dy,
                         int dyIdx,
                         int incy)

Exchange two vectors.

rcopy

public static void rcopy(int n,
                         float[] dx,
                         int dxIdx,
                         int incx,
                         float[] dy,
                         int dyIdx,
                         int incy)

Copy dx to dy.

raxpy

public static void raxpy(int n,
                         float da,
                         float[] dx,
                         int dxIdx,
                         int incx,
                         float[] dy,
                         int dyIdx,
                         int incy)

Compute dy <- da * dx + dy.

rzaxpy

public static void rzaxpy(int n,
                          float[] dz,
                          int dzIdx,
                          int incz,
                          float da,
                          float[] dx,
                          int dxIdx,
                          int incx,
                          float[] dy,
                          int dyIdx,
                          int incy)

Computes dz <- dx + dy

rzgxpy

public static void rzgxpy(int n,
                          float[] dz,
                          float[] dx,
                          float[] dy)

rdot

public static float rdot(int n,
                         float[] dx,
                         int dxIdx,
                         int incx,
                         float[] dy,
                         int dyIdx,
                         int incy)

Compute scalar product between dx and dy.