IDAMAX(3)

SYNOPSIS
INTEGER FUNCTION IDAMAX (N, DX, INCX)

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

LIBRARY
SLATEC (BLAS)

CATEGORY
D1A2

TYPE
DOUBLE 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) DX double precision vector with N elements INCX storage spacing between elements of DX --Output-- IDAMAX smallest index (zero if N .LE. 0) Find smallest index of maximum magnitude of double precision DX. IDAMAX = first I, I = 1 to N, to maximize ABS(DX(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
890531 Changed all specific intrinsics to generic. (WRB)
890531 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)