HP MLIB User's Guide Vol. 1 7th Ed.

Chapter 2 Basic Vector Operations 49

Index of maximum element of vector ISMAX/IDMAX/IIMAX

Name ISMAX/IDMAX/IIMAX

Index of maximum element of vector

Purpose Given a real or integer vector x of length n, these subprograms determine the

index of the maximum element of the vector. Speciﬁcally, the subprograms

determine the smallest index i such that

The vector can be stored in a one-dimensional array or in either a row or a

column of a two-dimensional array.

Usage VECLIB:

INTEGER*4 i, ISMAX, n, incx

REAL*4 x(lenx)

i = ISMAX(n, x, incx)

INTEGER*4 i, IDMAX, n, incx

REAL*8 x(lenx)

i = IDMAX(n, x, incx)

INTEGER*4 i, IIMAX, n, incx, x(lenx)

i = IIMAX(n, x, incx)

VECLIB8:

INTEGER*8 i, ISMAX, n, incx

REAL*4 x(lenx)

i = ISMAX(n, x, incx)

INTEGER*8 i, IDMAX, n, incx

REAL*8 x(lenx)

i = IDMAX(n, x, incx)

INTEGER*8 i, IIMAX, n, incx, x(lenx)

i = IIMAX(n, x, incx)

Input n Number of elements of vector x to be used. If n ≤ 0, the

subprograms do not reference x.

x Array of length lenx = (n−1)×|incx|+1 containing the

n-vector x.

incx Increment for the array x. x is stored forward in array x

with increment |incx|; that is, x

is stored in

x((i−1)×|incx|+1).

max x

: j 12… n,, ,=

()