ISAMAX, IDAMAX, ICAMAX, or IZAMAX Function

Purpose

Finds the index of element having maximum absolute value.

Library

BLAS Library (libblas.a)

FORTRAN Syntax

INTEGER FUNCTION ISAMAX(N,X,INCX)
INTEGER  INCX, N
REAL  X(*)

INTEGER FUNCTION IDAMAX(N,X,INCX)
INTEGER INCX,N
DOUBLE PRECISION X(*)
INTEGER FUNCTION ICAMAX(N,X,INCX)
INTEGER INCX,N
COMPLEX X(*)
INTEGER FUNCTION IZAMAX(N,X,INCX)
INTEGER INCX,N
COMPLEX*16 X(*)

Description

The ISAMAX, IDAMAX, ICAMAX, or IZAMAX function returns the index of element having maximum absolute value.

Parameters

Item Description
N On entry, N specifies the number of elements in X and Y; unchanged on exit.
X Vector of dimension at least (1 + (N-1) * abs(INCX) ); unchanged on exit.
INCX On entry, INCX specifies the increment for the elements of X; unchanged on exit.

Error Codes

For values of N <= 0, a value of 0 is returned.