01:       SUBROUTINE ZLAR2V( N, X, Y, Z, INCX, C, S, INCC )
02: *
03: *  -- LAPACK auxiliary routine (version 3.2) --
04: *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
05: *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
06: *     November 2006
07: *
08: *     .. Scalar Arguments ..
09:       INTEGER            INCC, INCX, N
10: *     ..
11: *     .. Array Arguments ..
12:       DOUBLE PRECISION   C( * )
13:       COMPLEX*16         S( * ), X( * ), Y( * ), Z( * )
14: *     ..
15: *
16: *  Purpose
17: *  =======
18: *
19: *  ZLAR2V applies a vector of complex plane rotations with real cosines
20: *  from both sides to a sequence of 2-by-2 complex Hermitian matrices,
21: *  defined by the elements of the vectors x, y and z. For i = 1,2,...,n
22: *
23: *     (       x(i)  z(i) ) :=
24: *     ( conjg(z(i)) y(i) )
25: *
26: *       (  c(i) conjg(s(i)) ) (       x(i)  z(i) ) ( c(i) -conjg(s(i)) )
27: *       ( -s(i)       c(i)  ) ( conjg(z(i)) y(i) ) ( s(i)        c(i)  )
28: *
29: *  Arguments
30: *  =========
31: *
32: *  N       (input) INTEGER
33: *          The number of plane rotations to be applied.
34: *
35: *  X       (input/output) COMPLEX*16 array, dimension (1+(N-1)*INCX)
36: *          The vector x; the elements of x are assumed to be real.
37: *
38: *  Y       (input/output) COMPLEX*16 array, dimension (1+(N-1)*INCX)
39: *          The vector y; the elements of y are assumed to be real.
40: *
41: *  Z       (input/output) COMPLEX*16 array, dimension (1+(N-1)*INCX)
42: *          The vector z.
43: *
44: *  INCX    (input) INTEGER
45: *          The increment between elements of X, Y and Z. INCX > 0.
46: *
47: *  C       (input) DOUBLE PRECISION array, dimension (1+(N-1)*INCC)
48: *          The cosines of the plane rotations.
49: *
50: *  S       (input) COMPLEX*16 array, dimension (1+(N-1)*INCC)
51: *          The sines of the plane rotations.
52: *
53: *  INCC    (input) INTEGER
54: *          The increment between elements of C and S. INCC > 0.
55: *
56: *  =====================================================================
57: *
58: *     .. Local Scalars ..
59:       INTEGER            I, IC, IX
60:       DOUBLE PRECISION   CI, SII, SIR, T1I, T1R, T5, T6, XI, YI, ZII,
61:      $                   ZIR
62:       COMPLEX*16         SI, T2, T3, T4, ZI
63: *     ..
64: *     .. Intrinsic Functions ..
65:       INTRINSIC          DBLE, DCMPLX, DCONJG, DIMAG
66: *     ..
67: *     .. Executable Statements ..
68: *
69:       IX = 1
70:       IC = 1
71:       DO 10 I = 1, N
72:          XI = DBLE( X( IX ) )
73:          YI = DBLE( Y( IX ) )
74:          ZI = Z( IX )
75:          ZIR = DBLE( ZI )
76:          ZII = DIMAG( ZI )
77:          CI = C( IC )
78:          SI = S( IC )
79:          SIR = DBLE( SI )
80:          SII = DIMAG( SI )
81:          T1R = SIR*ZIR - SII*ZII
82:          T1I = SIR*ZII + SII*ZIR
83:          T2 = CI*ZI
84:          T3 = T2 - DCONJG( SI )*XI
85:          T4 = DCONJG( T2 ) + SI*YI
86:          T5 = CI*XI + T1R
87:          T6 = CI*YI - T1R
88:          X( IX ) = CI*T5 + ( SIR*DBLE( T4 )+SII*DIMAG( T4 ) )
89:          Y( IX ) = CI*T6 - ( SIR*DBLE( T3 )-SII*DIMAG( T3 ) )
90:          Z( IX ) = CI*T3 + DCONJG( SI )*DCMPLX( T6, T1I )
91:          IX = IX + INCX
92:          IC = IC + INCC
93:    10 CONTINUE
94:       RETURN
95: *
96: *     End of ZLAR2V
97: *
98:       END
99: