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SLASV2(l)					)					SLASV2(l)

NAME
       SLASV2  - compute the singular value decomposition of a 2-by-2 triangular matrix [ F G ] [
       0 H ]

SYNOPSIS
       SUBROUTINE SLASV2( F, G, H, SSMIN, SSMAX, SNR, CSR, SNL, CSL )

	   REAL 	  CSL, CSR, F, G, H, SNL, SNR, SSMAX, SSMIN

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 singu-
       lar 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.

LAPACK version 3.0			   15 June 2000 				SLASV2(l)
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