org.netlib.lapack
Class Slasv2

java.lang.Object
  org.netlib.lapack.Slasv2

public class Slasv2
extends java.lang.Object

Following is the description from the original
Fortran source.  For each array argument, the Java
version will include an integer offset parameter, so
the arguments may not match the description exactly.
Contact seymour@cs.utk.edu with any questions.


 *     ..
 *
 *  Purpose
 *  =======
 *
 *  SLASV2 computes the singular value decomposition of a 2-by-2
 *  triangular matrix
 *     [  F   G  ]
 *     [  0   H  ].
 *  On return, abs(SSMAX) is the larger singular value, abs(SSMIN) is the
 *  smaller singular value, and (CSL,SNL) and (CSR,SNR) are the left and

 *  right singular vectors for abs(SSMAX), giving the decomposition
 *
 *     [ CSL  SNL ] [  F   G  ] [ CSR -SNR ]  =  [ SSMAX   0   ]
 *     [-SNL  CSL ] [  0   H  ] [ SNR  CSR ]     [  0    SSMIN ].
 *
 *  Arguments
 *  =========
 *
 *  F       (input) REAL
 *          The (1,1) element of the 2-by-2 matrix.
 *
 *  G       (input) REAL
 *          The (1,2) element of the 2-by-2 matrix.
 *
 *  H       (input) REAL
 *          The (2,2) element of the 2-by-2 matrix.
 *
 *  SSMIN   (output) REAL
 *          abs(SSMIN) is the smaller singular value.
 *
 *  SSMAX   (output) REAL
 *          abs(SSMAX) is the larger singular value.
 *
 *  SNL     (output) REAL
 *  CSL     (output) REAL
 *          The vector (CSL, SNL) is a unit left singular vector for the

 *          singular value abs(SSMAX).
 *
 *  SNR     (output) REAL
 *  CSR     (output) REAL
 *          The vector (CSR, SNR) is a unit right singular vector for the
 *          singular value abs(SSMAX).
 *
 *  Further Details
 *  ===============
 *
 *  Any input parameter may be aliased with any output parameter.
 *
 *  Barring over/underflow and assuming a guard digit in subtraction, all
 *  output quantities are correct to within a few units in the last
 *  place (ulps).
 *
 *  In IEEE arithmetic, the code works correctly if one matrix element is
 *  infinite.
 *
 *  Overflow will not occur unless the largest singular value itself
 *  overflows or is within a few ulps of overflow. (On machines with
 *  partial overflow, like the Cray, overflow may occur if the largest
 *  singular value is within a factor of 2 of overflow.)
 *
 *  Underflow is harmless if underflow is gradual. Otherwise, results
 *  may correspond to a matrix modified by perturbations of size near
 *  the underflow threshold.
 *
 * =====================================================================

 *
 *     .. Parameters ..

Constructor Summary

Slasv2()

Method Summary

static void

slasv2(float f, float g, float h, floatW ssmin, floatW ssmax, floatW snr, floatW csr, floatW snl, floatW csl)

Methods inherited from class java.lang.Object

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

Constructor Detail

Slasv2

public Slasv2()

Method Detail

slasv2

public static void slasv2(float f,
                          float g,
                          float h,
                          floatW ssmin,
                          floatW ssmax,
                          floatW snr,
                          floatW csr,
                          floatW snl,
                          floatW csl)