swap(3F)

NAME
     SSWAP, DSWAP, CSWAP, ZSWAP - Swaps two real or complex vectors

SYNOPSIS
     Real

        CALL SSWAP (n, x, incx, y, incy)

     Double precision

        CALL DSWAP (n, x, incx, y, incy)

     Complex

        CALL CSWAP (n, x, incx, y, incy)

     Double complex

        CALL ZSWAP (n, x, incx, y, incy)

DESCRIPTION
     SSWAP/DSWAP swaps two real vectors.

     CSWAP/ZSWAP swaps two complex vectors.

     These routines perform the following vector operation:

               x  <->  y

     where x and y are real or complex vectors.

     These routines have the following arguments:

     n         Integer.  (input)
               Number of vector elements to be swapped.  If n <= 0, these
               routines return without any computation.

     x         Array of dimension (n-1) * |incx| + 1.  (input and output)
               SSWAP: Real array.
               DSWAP: Double precision array.
               CSWAP: Complex array.
               ZSWAP: Double complex array.
               Vector to be swapped.

     incx      Integer.  (input)
               Increment between elements of x.
               If incx = 0, the results will be unpredictable.

     y         Array of dimension (n-1) * |incy| + 1.  (input and output)
               SSWAP: Real array.
               DSWAP: Double precision array.
               CSWAP: Complex array.
               ZSWAP: Double complex array.
               Vector to be swapped.

     incy      Integer.  (input)
               Increment between elements of y.  If incy = 0, the results
               will be unpredictable.

NOTES
     These routines are Level 1 Basic Linear Algebra Subprograms (Level 1
     BLAS).

     When working backward (incx < 0 or incy < 0), each routine starts at
     the end of the vector and moves backward, as follows:

          x(1-incx * (n-1)), x(1-incx * (n-2)), ..., x(1)

          y(1-incy * (n-1)), y(1-incy * (n-2)), ..., y(1)