HP MLIB User's Guide Vol. 1 7th Ed.

Chapter 2 Basic Vector Operations 115

Apply Givens rotation SROT/DROT/CROT/CSROT/ZROT/ZDROT

INTEGER*4 n, incx, incy

REAL*8 c, s

COMPLEX*16 x(lenx), y(leny)

CALL ZDROT(n, x, incx, y, incy, c, s)

VECLIB8:

INTEGER*8 n, incx, incy

REAL*4 x(lenx), y(leny), c, s

CALL SROT(n, x, incx, y, incy, c, s)

INTEGER*8 n, incx, incy

REAL*8 x(lenx), y(leny), c, s

CALL DROT(n, x, incx, y, incy, c, s)

INTEGER*8 n, incx, incy

REAL*4 c

COMPLEX*8 x(lenx), y(leny), s

CALL CROT(n, x, incx, y, incy, c, s)

INTEGER*8 n, incx, incy

REAL*4 c, s

COMPLEX*8 x(lenx), y(leny)

CALL CSROT(n, x, incx, y, incy, c, s)

INTEGER*8 n, incx, incy

REAL*8 c

COMPLEX*16 x(lenx), y(leny), s

CALL ZROT(n, x, incx, y, incy, c, s)

INTEGER*8 n, incx, incy

REAL*8 c, s

COMPLEX*16 x(lenx), y(leny)

CALL ZDROT(n, x, incx, y, incy, c, s)

Input n Number of elements of vectors x and y to be used in the

Givens rotation. If n ≤ 0, the subprograms do not

reference x or y.

x Array of length lenx = (n−1)×|incx|+1 containing the

n-vector x.

incx Increment for the array x, incx ≠ 0:

incx > 0 x is stored forward in array x; that is,

is stored in x((i−1)×incx+1).