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CentOS 7.0 - man page for slasv2 (centos section 3)

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slasv2.f(3)				      LAPACK				      slasv2.f(3)

NAME
       slasv2.f -

SYNOPSIS
   Functions/Subroutines
       subroutine slasv2 (F, G, H, SSMIN, SSMAX, SNR, CSR, SNL, CSL)
	   SLASV2 computes the singular value decomposition of a 2-by-2 triangular matrix.

Function/Subroutine Documentation
   subroutine slasv2 (realF, realG, realH, realSSMIN, realSSMAX, realSNR, realCSR, realSNL,
       realCSL)
       SLASV2 computes the singular value decomposition of a 2-by-2 triangular matrix.

       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 ].

       Parameters:
	   F

		     F is REAL
		     The (1,1) element of the 2-by-2 matrix.

	   G

		     G is REAL
		     The (1,2) element of the 2-by-2 matrix.

	   H

		     H is REAL
		     The (2,2) element of the 2-by-2 matrix.

	   SSMIN

		     SSMIN is REAL
		     abs(SSMIN) is the smaller singular value.

	   SSMAX

		     SSMAX is REAL
		     abs(SSMAX) is the larger singular value.

	   SNL

		     SNL is REAL

	   CSL

		     CSL is REAL
		     The vector (CSL, SNL) is a unit left singular vector for the
		     singular value abs(SSMAX).

	   SNR

		     SNR is REAL

	   CSR

		     CSR is REAL
		     The vector (CSR, SNR) is a unit right singular vector for the
		     singular value abs(SSMAX).

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   September 2012

       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.

       Definition at line 139 of file slasv2.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2				 Tue Sep 25 2012			      slasv2.f(3)
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