Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 6/24/2024
Public

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

?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

  • mkl.fi

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

REAL for srot

DOUBLE PRECISION for drot

COMPLEX for crot

DOUBLE COMPLEX 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

REAL for srot

DOUBLE PRECISION for drot

COMPLEX for crot

DOUBLE COMPLEX for zrot

Values that define a rotation


Equation

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.