ISAMAX(3)

SYNOPSIS
INTEGER FUNCTION ISAMAX (N, SX, INCX)

NAME
isamax - Find the smallest index of that component of a vector having the maximum magnitude.

LIBRARY
SLATEC (BLAS)

CATEGORY
D1A2

TYPE
SINGLE PRECISION (ISAMAX-S, IDAMAX-D, ICAMAX-C)

KEYWORDS
BLAS, LINEAR ALGEBRA, MAXIMUM COMPONENT, VECTOR

AUTHOR
Lawson, C. L., (JPL) Hanson, R. J., (SNLA) Kincaid, D. R., (U. of Texas) Krogh, F. T., (JPL)

DESCRIPTION
B L A S Subprogram Description of Parameters --Input-- N number of elements in input vector(s) SX single precision vector with N elements INCX storage spacing between elements of SX --Output-- ISAMAX smallest index (zero if N .LE. 0) Find smallest index of maximum magnitude of single precision SX. ISAMAX = first I, I = 1 to N, to maximize ABS(SX(IX+(I-1)*INCX)), where IX = 1 if INCX .GE. 0, else IX = 1+(1-N)*INCX.

REFERENCES
C. L. Lawson, R. J. Hanson, D. R. Kincaid and F. T. Krogh, Basic linear algebra subprograms for Fortran usage, Algorithm No. 539, Transactions on Mathematical Software 5, 3 (September 1979), pp. 308-323.

ROUTINES CALLED
(NONE)

REVISION HISTORY (YYMMDD)
791001 DATE WRITTEN
861211 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)
900821 Modified to correct problem with a negative increment. (WRB)
920501 Reformatted the REFERENCES section. (WRB)
920618 Slight restructuring of code. (RWC, WRB)