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/* ../blas/src/crotg.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"
/* Subroutine */ int REF_crotg_(complex *ca, complex *cb, real *c__, complex *s)
{
/* System generated locals */
real r__1, r__2;
complex q__1, q__2, q__3;
/* Builtin functions */
double c_abs(complex *), sqrt(doublereal);
void r_cnjg(complex *, complex *);
/* Local variables */
static real norm;
static complex alpha;
static real scale;
if (c_abs(ca) != 0.f) {
goto L10;
}
*c__ = 0.f;
s->r = 1.f, s->i = 0.f;
ca->r = cb->r, ca->i = cb->i;
goto L20;
L10:
scale = c_abs(ca) + c_abs(cb);
q__1.r = ca->r / scale, q__1.i = ca->i / scale;
/* Computing 2nd power */
r__1 = c_abs(&q__1);
q__2.r = cb->r / scale, q__2.i = cb->i / scale;
/* Computing 2nd power */
r__2 = c_abs(&q__2);
norm = scale * sqrt(r__1 * r__1 + r__2 * r__2);
r__1 = c_abs(ca);
q__1.r = ca->r / r__1, q__1.i = ca->i / r__1;
alpha.r = q__1.r, alpha.i = q__1.i;
*c__ = c_abs(ca) / norm;
r_cnjg(&q__3, cb);
q__2.r = alpha.r * q__3.r - alpha.i * q__3.i, q__2.i = alpha.r * q__3.i +
alpha.i * q__3.r;
q__1.r = q__2.r / norm, q__1.i = q__2.i / norm;
s->r = q__1.r, s->i = q__1.i;
q__1.r = norm * alpha.r, q__1.i = norm * alpha.i;
ca->r = q__1.r, ca->i = q__1.i;
L20:
return 0;
} /* crotg_ */
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