subroutine clar2v	(	integer	N,
		complex, dimension( * )	X,
		complex, dimension( * )	Y,
		complex, dimension( * )	Z,
		integer	INCX,
		real, dimension( * )	C,
		complex, dimension( * )	S,
		integer	INCC
	)

CLAR2V applies a vector of plane rotations with real cosines and complex sines from both sides to a sequence of 2-by-2 symmetric/Hermitian matrices.

Download CLAR2V + dependencies [TGZ] [ZIP] [TXT]

Purpose:

 CLAR2V applies a vector of complex plane rotations with real cosines
 from both sides to a sequence of 2-by-2 complex Hermitian matrices,
 defined by the elements of the vectors x, y and z. For i = 1,2,...,n

    (       x(i)  z(i) ) :=
    ( conjg(z(i)) y(i) )

      (  c(i) conjg(s(i)) ) (       x(i)  z(i) ) ( c(i) -conjg(s(i)) )
      ( -s(i)       c(i)  ) ( conjg(z(i)) y(i) ) ( s(i)        c(i)  )

Parameters

[in]	N	N is INTEGER The number of plane rotations to be applied.
[in,out]	X	X is COMPLEX array, dimension (1+(N-1)*INCX) The vector x; the elements of x are assumed to be real.
[in,out]	Y	Y is COMPLEX array, dimension (1+(N-1)*INCX) The vector y; the elements of y are assumed to be real.
[in,out]	Z	Z is COMPLEX array, dimension (1+(N-1)*INCX) The vector z.
[in]	INCX	INCX is INTEGER The increment between elements of X, Y and Z. INCX > 0.
[in]	C	C is REAL array, dimension (1+(N-1)*INCC) The cosines of the plane rotations.
[in]	S	S is COMPLEX array, dimension (1+(N-1)*INCC) The sines of the plane rotations.
[in]	INCC	INCC is INTEGER The increment between elements of C and S. INCC > 0.

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Date

September 2012

Definition at line 113 of file clar2v.f.

*
*  -- LAPACK auxiliary routine (version 3.4.2) --
*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
*     September 2012
*
*     .. Scalar Arguments ..
      INTEGER            incc, incx, n
*     ..
*     .. Array Arguments ..
      REAL               c( * )
      COMPLEX            s( * ), x( * ), y( * ), z( * )
*     ..
*
*  =====================================================================
*
*     .. Local Scalars ..
      INTEGER            i, ic, ix
      REAL               ci, sii, sir, t1i, t1r, t5, t6, xi, yi, zii,
     $                   zir
      COMPLEX            si, t2, t3, t4, zi
*     ..
*     .. Intrinsic Functions ..
      INTRINSIC          aimag, cmplx, conjg, real
*     ..
*     .. Executable Statements ..
*
      ix = 1
      ic = 1
      DO 10 i = 1, n
         xi = REAL( X( IX ) )
         yi = REAL( Y( IX ) )
         zi = z( ix )
         zir = REAL( zi )
         zii = aimag( zi )
         ci = c( ic )
         si = s( ic )
         sir = REAL( si )
         sii = aimag( si )
         t1r = sir*zir - sii*zii
         t1i = sir*zii + sii*zir
         t2 = ci*zi
         t3 = t2 - conjg( si )*xi
         t4 = conjg( t2 ) + si*yi
         t5 = ci*xi + t1r
         t6 = ci*yi - t1r
         x( ix ) = ci*t5 + ( sir*REAL( t4 )+sii*aimag( t4 ) )
         y( ix ) = ci*t6 - ( sir*REAL( t3 )-sii*aimag( t3 ) )
         z( ix ) = ci*t3 + conjg( si )*cmplx( t6, t1i )
         ix = ix + incx
         ic = ic + incc
   10 CONTINUE
      RETURN
*
*     End of CLAR2V
*

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