?rot

Applies a plane rotation with real cosine and complex sine to a pair of complex vectors.

Syntax

call crot( n, cx, incx, cy, incy, c, s )

call zrot( n, cx, incx, cy, incy, c, s )

Include Files

The FORTRAN 77 interfaces are specified in the mkl_lapack.fi include file (to be used in Fortran programs) and in the mkl_lapack.h include file (to be used in C programs).

Description

The routine applies a plane rotation, where the cosine (c) is real and the sine (s) is complex, and the vectors cx and cy are complex. This routine has its real equivalents in BLAS (see ?rot in Chapter "BLAS and Sparse BLAS Routines").

Input Parameters

n

INTEGER. The number of elements in the vectors cx and cy.

cx, cy

COMPLEX for crot

COMPLEX*16 for zrot

Arrays of dimension (n), contain input vectors x and y, respectively.

incx

INTEGER. The increment between successive elements of cx.

incy

INTEGER. The increment between successive elements of cy.

c

REAL for crot

DOUBLE PRECISION for zrot

s

COMPLEX for crot

COMPLEX*16 for zrot

Values that define a rotation

where c*c + s*conjg(s) = 1.0.

Output Parameters

cx: On exit, overwritten with c*x + s*y.
cy: On exit, overwritten with -conjg(s)*x + c*y.