org.jblas
Class JavaBlas

java.lang.Object
  extended by 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
JavaBlas()
           
 
Method Summary
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.



written by Mikio L. Braun and Johannes Schaback