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zrot

 NAME
      ZROT - apply a plane rotation, where the cos (C) is real and
      the sin (S) is complex, and the vectors CX and CY are com-
      plex

 SYNOPSIS
      SUBROUTINE ZROT( N, CX, INCX, CY, INCY, C, S )

          INTEGER      INCX, INCY, N

          DOUBLE       PRECISION C

          COMPLEX*16   S

          COMPLEX*16   CX( * ), CY( * )

 PURPOSE
      ZROT   applies a plane rotation, where the cos (C) is real
      and the sin (S) is complex, and the vectors CX and CY are
      complex.

 ARGUMENTS
      N       (input) INTEGER
              The number of elements in the vectors CX and CY.

      CX      (input/output) COMPLEX*16 array, dimension (N)
              On input, the vector X.  On output, CX is overwrit-
              ten with C*X + S*Y.

      INCX    (input) INTEGER
              The increment between successive values of CY.  INCX
              <> 0.

      CY      (input/output) COMPLEX*16 array, dimension (N)
              On input, the vector Y.  On output, CY is overwrit-
              ten with -CONJG(S)*X + C*Y.

      INCY    (input) INTEGER
              The increment between successive values of CY.  INCX
              <> 0.

      C       (input) DOUBLE PRECISION
              S       (input) COMPLEX*16 C and S define a rotation
              [  C          S  ] [ -conjg(S)   C  ] where C*C +
              S*CONJG(S) = 1.0.