hemv(3F)

NAME
     CHEMV, ZHEMV - Multiplies a complex vector by a complex Hermitian
     matrix

SYNOPSIS
     Complex

        CALL CHEMV (uplo, n, alpha, a, lda, x, incx, beta, y, incy)

     Double complex

        CALL ZHEMV (uplo, n, alpha, a, lda, x, incx, beta, y, incy)

DESCRIPTION
     These routines perform the following matrix-vector operation:

          y <- alpha Ax + beta y

     where alpha and beta are scalars, x and y are n-element vectors, and A
     is an n-by-n Hermitian matrix.

     These routines have the following arguments:

     uplo      Character*1.  (input)
               Specifies whether the upper or lower triangular part of
               array a is referenced, as follows:

               uplo= 'U' or 'u': only the upper triangular part of a is
               referenced.
               uplo= 'L' or 'l': only the lower triangular part of a is
               referenced.

     n         Integer.  (input)
               Specifies the order of matrix A.  n >= 0.

     alpha     Scalar alpha.  (input)
               CHEMV: Complex.
               ZHEMV: Double complex.

     a         Array of dimension (lda,n).  (input)
               CHEMV: Complex array.
               ZHEMV: Double complex array.

               Before entry with uplo = 'U' or 'u', the leading n-by-n
               upper triangular part of array a must contain the upper
               triangular part of the Hermitian matrix.  The strictly lower
               triangular part of a is not referenced.

               Before entry with uplo = 'L' or 'l', the leading n-by-n
               lower triangular part of array a must contain the lower
               triangular part of the Hermitian matrix.  The strictly upper
               triangular part of a is not referenced.

               The imaginary parts of the diagonal elements need not be set
               and are assumed to be 0.

     lda       Integer.  (input)
               Specifies the first dimension of a as declared in the
               calling program.
               Argument lda >= MAX(1,n).

     x         Array of dimension 1+(n-1) * |incx|.  (input)
               CHEMV: Complex array.
               ZHEMV: Double complex array.
               Contains vector x.

     incx      Integer.  (input)
               Specifies the increment for the elements of x.  incx must
               not be 0.

     beta      Scalar beta.  If beta is supplied as 0, y need not be set on
               input.
               CHEMV: Complex.
               ZHEMV: Double complex.

     y         Array of dimension 1+(n-1) * |incy|.  (input and output)
               CHEMV: Complex array.
               ZHEMV: Double complex array.
               Contains vector y.  On exit, the updated vector overwrites
               array y.

     incy      Integer.  (input)
               Specifies the increment for the elements of y.  incy must
               not be 0.

NOTES
     CHEMV/ZHEMV is a Level 2 Basic Linear Algebra Subprogram (Level 2
     BLAS).

     When working backward (incx < 0 or incy < 0), this 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)

SEE ALSO
     SYMV(3F)