1: SUBROUTINE DLARTV( N, X, INCX, Y, INCY, C, S, INCC )
2: *
3: * -- LAPACK auxiliary routine (version 3.2) --
4: * -- LAPACK is a software package provided by Univ. of Tennessee, --
5: * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
6: * November 2006
7: *
8: * .. Scalar Arguments ..
9: INTEGER INCC, INCX, INCY, N
10: * ..
11: * .. Array Arguments ..
12: DOUBLE PRECISION C( * ), S( * ), X( * ), Y( * )
13: * ..
14: *
15: * Purpose
16: * =======
17: *
18: * DLARTV applies a vector of real plane rotations to elements of the
19: * real vectors x and y. For i = 1,2,...,n
20: *
21: * ( x(i) ) := ( c(i) s(i) ) ( x(i) )
22: * ( y(i) ) ( -s(i) c(i) ) ( y(i) )
23: *
24: * Arguments
25: * =========
26: *
27: * N (input) INTEGER
28: * The number of plane rotations to be applied.
29: *
30: * X (input/output) DOUBLE PRECISION array,
31: * dimension (1+(N-1)*INCX)
32: * The vector x.
33: *
34: * INCX (input) INTEGER
35: * The increment between elements of X. INCX > 0.
36: *
37: * Y (input/output) DOUBLE PRECISION array,
38: * dimension (1+(N-1)*INCY)
39: * The vector y.
40: *
41: * INCY (input) INTEGER
42: * The increment between elements of Y. INCY > 0.
43: *
44: * C (input) DOUBLE PRECISION array, dimension (1+(N-1)*INCC)
45: * The cosines of the plane rotations.
46: *
47: * S (input) DOUBLE PRECISION array, dimension (1+(N-1)*INCC)
48: * The sines of the plane rotations.
49: *
50: * INCC (input) INTEGER
51: * The increment between elements of C and S. INCC > 0.
52: *
53: * =====================================================================
54: *
55: * .. Local Scalars ..
56: INTEGER I, IC, IX, IY
57: DOUBLE PRECISION XI, YI
58: * ..
59: * .. Executable Statements ..
60: *
61: IX = 1
62: IY = 1
63: IC = 1
64: DO 10 I = 1, N
65: XI = X( IX )
66: YI = Y( IY )
67: X( IX ) = C( IC )*XI + S( IC )*YI
68: Y( IY ) = C( IC )*YI - S( IC )*XI
69: IX = IX + INCX
70: IY = IY + INCY
71: IC = IC + INCC
72: 10 CONTINUE
73: RETURN
74: *
75: * End of DLARTV
76: *
77: END
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