/*  -- translated by f2c (version 20100827).
   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 igraphdrot_(integer *n, doublereal *dx, integer *incx, 
	doublereal *dy, integer *incy, doublereal *c__, doublereal *s)
{
    /* System generated locals */
    integer i__1;

    /* Local variables */
    integer i__, ix, iy;
    doublereal dtemp;


/*  Purpose   
    =======   

       DROT applies a plane rotation.   

    Further Details   
    ===============   

       jack dongarra, linpack, 3/11/78.   
       modified 12/3/93, array(1) declarations changed to array(*)   

    =====================================================================   

       Parameter adjustments */
    --dy;
    --dx;

    /* Function Body */
    if (*n <= 0) {
	return 0;
    }
    if (*incx == 1 && *incy == 1) {

/*       code for both increments equal to 1 */

	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    dtemp = *c__ * dx[i__] + *s * dy[i__];
	    dy[i__] = *c__ * dy[i__] - *s * dx[i__];
	    dx[i__] = dtemp;
	}
    } else {

/*       code for unequal increments or equal increments not equal   
           to 1 */

	ix = 1;
	iy = 1;
	if (*incx < 0) {
	    ix = (-(*n) + 1) * *incx + 1;
	}
	if (*incy < 0) {
	    iy = (-(*n) + 1) * *incy + 1;
	}
	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    dtemp = *c__ * dx[ix] + *s * dy[iy];
	    dy[iy] = *c__ * dy[iy] - *s * dx[ix];
	    dx[ix] = dtemp;
	    ix += *incx;
	    iy += *incy;
	}
    }
    return 0;
} /* igraphdrot_ */