VMS Help FORTRAN, Intrinsic Procedures, IxMAX  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  INTEGER*4 ISMAX (n, x, incx)
  INTEGER*4 IDMAX (n, x, incx)
  INTEGER*4 ICMAX (n, x, incx)
  INTEGER*4 IZMAX (n, x, incx)

  Functions that return the index of the first selected element of
  the array "x" that has the maximum value.

  These routines are part of the BLAS1 Extended Set, and are
  available only on VAX processors.  Compaq Extended Math Library
  product may be needed to resolve references to Extended Set
  routines that are not expanded inline by the compiler.

  Arguments

    n

    Integer number of elements in array "x" to be accessed.

    x

    Array containing the elements to be accessed or array reference
    to the first such element.  The data type is REAL*4 for ISMAX,
    REAL*8 for IDMAX, COMPLEX*8 for ICMAX, COMPLEX*16 for IZMAX.

    incx

    Integer index increment used in selecting which elements of array
    "x" are accessed.