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Class org.netlib.lapack.DLASV2

java.lang.Object
   |
   +----org.netlib.lapack.DLASV2

public class DLASV2

extends Object

DLASV2 is a simplified interface to the JLAPACK routine dlasv2.
This interface converts Java-style 2D row-major arrays into
the 1D column-major linearized arrays expected by the lower
level JLAPACK routines.  Using this interface also allows you
to omit offset and leading dimension arguments.  However, because
of these conversions, these routines will be slower than the low
level ones.  Following is the description from the original Fortran
source.  Contact seymour@cs.utk.edu with any questions.

 *     ..
 *
 *  Purpose
 *  =======
 *
 *  DLASV2 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) DOUBLE PRECISION
 *          The (1,1) element of the 2-by-2 matrix.
 *
 *  G       (input) DOUBLE PRECISION
 *          The (1,2) element of the 2-by-2 matrix.
 *
 *  H       (input) DOUBLE PRECISION
 *          The (2,2) element of the 2-by-2 matrix.
 *
 *  SSMIN   (output) DOUBLE PRECISION
 *          abs(SSMIN) is the smaller singular value.
 *
 *  SSMAX   (output) DOUBLE PRECISION
 *          abs(SSMAX) is the larger singular value.
 *
 *  SNL     (output) DOUBLE PRECISION
 *  CSL     (output) DOUBLE PRECISION
 *          The vector (CSL, SNL) is a unit left singular vector for the
 *          singular value abs(SSMAX).
 *
 *  SNR     (output) DOUBLE PRECISION
 *  CSR     (output) DOUBLE PRECISION
 *          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 ..

DLASV2()

DLASV2(double, double, double, doubleW, doubleW, doubleW, doubleW, doubleW, doubleW)

 public DLASV2()

 public static void DLASV2(double f,
                           double g,
                           double h,
                           doubleW ssmin,
                           doubleW ssmax,
                           doubleW snr,
                           doubleW csr,
                           doubleW snl,
                           doubleW csl)

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