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/* dlar2v.f -- translated by f2c (version 20061008).
You must link the resulting object file with libf2c:
on Microsoft Windows system, link with libf2c.lib;
on Linux or Unix systems, link with .../path/to/libf2c.a -lm
or, if you install libf2c.a in a standard place, with -lf2c -lm
-- in that order, at the end of the command line, as in
cc *.o -lf2c -lm
Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
http://www.netlib.org/f2c/libf2c.zip
*/
#include "f2c.h"
#include "blaswrap.h"
/* Subroutine */ int dlar2v_(integer *n, doublereal *x, doublereal *y,
doublereal *z__, integer *incx, doublereal *c__, doublereal *s,
integer *incc)
{
/* System generated locals */
integer i__1;
/* Local variables */
integer i__;
doublereal t1, t2, t3, t4, t5, t6;
integer ic;
doublereal ci, si;
integer ix;
doublereal xi, yi, zi;
/* -- LAPACK auxiliary routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* DLAR2V applies a vector of real plane rotations from both sides to */
/* a sequence of 2-by-2 real symmetric matrices, defined by the elements */
/* of the vectors x, y and z. For i = 1,2,...,n */
/* ( x(i) z(i) ) := ( c(i) s(i) ) ( x(i) z(i) ) ( c(i) -s(i) ) */
/* ( z(i) y(i) ) ( -s(i) c(i) ) ( z(i) y(i) ) ( s(i) c(i) ) */
/* Arguments */
/* ========= */
/* N (input) INTEGER */
/* The number of plane rotations to be applied. */
/* X (input/output) DOUBLE PRECISION array, */
/* dimension (1+(N-1)*INCX) */
/* The vector x. */
/* Y (input/output) DOUBLE PRECISION array, */
/* dimension (1+(N-1)*INCX) */
/* The vector y. */
/* Z (input/output) DOUBLE PRECISION array, */
/* dimension (1+(N-1)*INCX) */
/* The vector z. */
/* INCX (input) INTEGER */
/* The increment between elements of X, Y and Z. INCX > 0. */
/* C (input) DOUBLE PRECISION array, dimension (1+(N-1)*INCC) */
/* The cosines of the plane rotations. */
/* S (input) DOUBLE PRECISION array, dimension (1+(N-1)*INCC) */
/* The sines of the plane rotations. */
/* INCC (input) INTEGER */
/* The increment between elements of C and S. INCC > 0. */
/* ===================================================================== */
/* .. Local Scalars .. */
/* .. */
/* .. Executable Statements .. */
/* Parameter adjustments */
--s;
--c__;
--z__;
--y;
--x;
/* Function Body */
ix = 1;
ic = 1;
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
xi = x[ix];
yi = y[ix];
zi = z__[ix];
ci = c__[ic];
si = s[ic];
t1 = si * zi;
t2 = ci * zi;
t3 = t2 - si * xi;
t4 = t2 + si * yi;
t5 = ci * xi + t1;
t6 = ci * yi - t1;
x[ix] = ci * t5 + si * t4;
y[ix] = ci * t6 - si * t3;
z__[ix] = ci * t4 - si * t5;
ix += *incx;
ic += *incc;
/* L10: */
}
/* End of DLAR2V */
return 0;
} /* dlar2v_ */
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