00001 SUBROUTINE ZLAR2V( N, X, Y, Z, INCX, C, S, INCC ) 00002 * 00003 * -- LAPACK auxiliary routine (version 3.2) -- 00004 * -- LAPACK is a software package provided by Univ. of Tennessee, -- 00005 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- 00006 * November 2006 00007 * 00008 * .. Scalar Arguments .. 00009 INTEGER INCC, INCX, N 00010 * .. 00011 * .. Array Arguments .. 00012 DOUBLE PRECISION C( * ) 00013 COMPLEX*16 S( * ), X( * ), Y( * ), Z( * ) 00014 * .. 00015 * 00016 * Purpose 00017 * ======= 00018 * 00019 * ZLAR2V applies a vector of complex plane rotations with real cosines 00020 * from both sides to a sequence of 2-by-2 complex Hermitian matrices, 00021 * defined by the elements of the vectors x, y and z. For i = 1,2,...,n 00022 * 00023 * ( x(i) z(i) ) := 00024 * ( conjg(z(i)) y(i) ) 00025 * 00026 * ( c(i) conjg(s(i)) ) ( x(i) z(i) ) ( c(i) -conjg(s(i)) ) 00027 * ( -s(i) c(i) ) ( conjg(z(i)) y(i) ) ( s(i) c(i) ) 00028 * 00029 * Arguments 00030 * ========= 00031 * 00032 * N (input) INTEGER 00033 * The number of plane rotations to be applied. 00034 * 00035 * X (input/output) COMPLEX*16 array, dimension (1+(N-1)*INCX) 00036 * The vector x; the elements of x are assumed to be real. 00037 * 00038 * Y (input/output) COMPLEX*16 array, dimension (1+(N-1)*INCX) 00039 * The vector y; the elements of y are assumed to be real. 00040 * 00041 * Z (input/output) COMPLEX*16 array, dimension (1+(N-1)*INCX) 00042 * The vector z. 00043 * 00044 * INCX (input) INTEGER 00045 * The increment between elements of X, Y and Z. INCX > 0. 00046 * 00047 * C (input) DOUBLE PRECISION array, dimension (1+(N-1)*INCC) 00048 * The cosines of the plane rotations. 00049 * 00050 * S (input) COMPLEX*16 array, dimension (1+(N-1)*INCC) 00051 * The sines of the plane rotations. 00052 * 00053 * INCC (input) INTEGER 00054 * The increment between elements of C and S. INCC > 0. 00055 * 00056 * ===================================================================== 00057 * 00058 * .. Local Scalars .. 00059 INTEGER I, IC, IX 00060 DOUBLE PRECISION CI, SII, SIR, T1I, T1R, T5, T6, XI, YI, ZII, 00061 $ ZIR 00062 COMPLEX*16 SI, T2, T3, T4, ZI 00063 * .. 00064 * .. Intrinsic Functions .. 00065 INTRINSIC DBLE, DCMPLX, DCONJG, DIMAG 00066 * .. 00067 * .. Executable Statements .. 00068 * 00069 IX = 1 00070 IC = 1 00071 DO 10 I = 1, N 00072 XI = DBLE( X( IX ) ) 00073 YI = DBLE( Y( IX ) ) 00074 ZI = Z( IX ) 00075 ZIR = DBLE( ZI ) 00076 ZII = DIMAG( ZI ) 00077 CI = C( IC ) 00078 SI = S( IC ) 00079 SIR = DBLE( SI ) 00080 SII = DIMAG( SI ) 00081 T1R = SIR*ZIR - SII*ZII 00082 T1I = SIR*ZII + SII*ZIR 00083 T2 = CI*ZI 00084 T3 = T2 - DCONJG( SI )*XI 00085 T4 = DCONJG( T2 ) + SI*YI 00086 T5 = CI*XI + T1R 00087 T6 = CI*YI - T1R 00088 X( IX ) = CI*T5 + ( SIR*DBLE( T4 )+SII*DIMAG( T4 ) ) 00089 Y( IX ) = CI*T6 - ( SIR*DBLE( T3 )-SII*DIMAG( T3 ) ) 00090 Z( IX ) = CI*T3 + DCONJG( SI )*DCMPLX( T6, T1I ) 00091 IX = IX + INCX 00092 IC = IC + INCC 00093 10 CONTINUE 00094 RETURN 00095 * 00096 * End of ZLAR2V 00097 * 00098 END
1.7.2