clags2.f(3)							      LAPACK							       clags2.f(3)

NAME

       clags2.f -

SYNOPSIS

   Functions/Subroutines
       subroutine clags2 (UPPER, A1, A2, A3, B1, B2, B3, CSU, SNU, CSV, SNV, CSQ, SNQ)
	   CLAGS2

Function/Subroutine Documentation
   subroutine clags2 (logicalUPPER, realA1, complexA2, realA3, realB1, complexB2, realB3, realCSU, complexSNU, realCSV, complexSNV, realCSQ,
       complexSNQ)
       CLAGS2

       Purpose:

	    CLAGS2 computes 2-by-2 unitary matrices U, V and Q, such
	    that if ( UPPER ) then

		      U**H *A*Q = U**H *( A1 A2 )*Q = ( x  0  )
					( 0  A3 )     ( x  x  )
	    and
		      V**H*B*Q = V**H *( B1 B2 )*Q = ( x  0  )
				       ( 0  B3 )     ( x  x  )

	    or if ( .NOT.UPPER ) then

		      U**H *A*Q = U**H *( A1 0	)*Q = ( x  x  )
					( A2 A3 )     ( 0  x  )
	    and
		      V**H *B*Q = V**H *( B1 0	)*Q = ( x  x  )
					( B2 B3 )     ( 0  x  )
	    where

	      U = (   CSU    SNU ), V = (  CSV	  SNV ),
		  ( -SNU**H  CSU )	( -SNV**H CSV )

	      Q = (   CSQ    SNQ )
		  ( -SNQ**H  CSQ )

	    The rows of the transformed A and B are parallel. Moreover, if the
	    input 2-by-2 matrix A is not zero, then the transformed (1,1) entry
	    of A is not zero. If the input matrices A and B are both not zero,
	    then the transformed (2,2) element of B is not zero, except when the
	    first rows of input A and B are parallel and the second rows are
	    zero.

       Parameters:
	   UPPER

		     UPPER is LOGICAL
		     = .TRUE.: the input matrices A and B are upper triangular.
		     = .FALSE.: the input matrices A and B are lower triangular.

	   A1

		     A1 is REAL

	   A2

		     A2 is COMPLEX

	   A3

		     A3 is REAL
		     On entry, A1, A2 and A3 are elements of the input 2-by-2
		     upper (lower) triangular matrix A.

	   B1

		     B1 is REAL

	   B2

		     B2 is COMPLEX

	   B3

		     B3 is REAL
		     On entry, B1, B2 and B3 are elements of the input 2-by-2
		     upper (lower) triangular matrix B.

	   CSU

		     CSU is REAL

	   SNU

		     SNU is COMPLEX
		     The desired unitary matrix U.

	   CSV

		     CSV is REAL

	   SNV

		     SNV is COMPLEX
		     The desired unitary matrix V.

	   CSQ

		     CSQ is REAL

	   SNQ

		     SNQ is COMPLEX
		     The desired unitary matrix Q.

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       Definition at line 158 of file clags2.f.

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

Version 3.4.2							  Tue Sep 25 2012						       clags2.f(3)