SDZRO(3)

SYNOPSIS
SUBROUTINE SDZRO (AE, F, H, N, NQ, IROOT, RE, T, YH, UROUND, B, C, 8 FB, FC, Y)

NAME
sdzro - SDZRO searches for a zero of a function F(N, T, Y, IROOT) between the given values B and C until the width of the interval (B, C) has collapsed to within a tolerance specified by the stopping criterion, ABS(B - C) .LE. 2.*(RW*ABS(B) + AE).

LIBRARY
SLATEC (SDRIVE)

TYPE
SINGLE PRECISION (SDZRO-S, DDZRO-D, CDZRO-C)

AUTHOR
Kahaner, D. K., (NIST) National Institute of Standards and Technology Gaithersburg, MD 20899 Sutherland, C. D., (LANL) Mail Stop D466 Los Alamos National Laboratory Los Alamos, NM 87545

DESCRIPTION
This is a special purpose version of ZEROIN, modified for use with the SDRIV package. Sandia Mathematical Program Library Mathematical Computing Services Division 5422 Sandia Laboratories P. O. Box 5800 Albuquerque, New Mexico 87115 Control Data 6600 Version 4.5, 1 November 1971 PARAMETERS F - Name of the external function, which returns a real result. This name must be in an EXTERNAL statement in the calling program. B - One end of the interval (B, C). The value returned for B usually is the better approximation to a zero of F. C - The other end of the interval (B, C). RE - Relative error used for RW in the stopping criterion. If the requested RE is less than machine precision, then RW is set to approximately machine precision. AE - Absolute error used in the stopping criterion. If the given interval (B, C) contains the origin, then a nonzero value should be chosen for AE.

REFERENCES
L. F. Shampine and H. A. Watts, ZEROIN, a root-solving routine, SC-TM-70-631, Sept 1970. T. J. Dekker, Finding a zero by means of successive linear interpolation, Constructive Aspects of the Fundamental Theorem of Algebra, edited by B. Dejon and P. Henrici, 1969.

ROUTINES CALLED
SDNTP

REVISION HISTORY (YYMMDD)
790601 DATE WRITTEN
900329 Initial submission to SLATEC.