POLINT(3)

SYNOPSIS
SUBROUTINE POLINT (N, X, Y, C)

NAME
polint - Produce the polynomial which interpolates a set of discrete data points.

LIBRARY
SLATEC

CATEGORY
E1B

TYPE
SINGLE PRECISION (POLINT-S, DPLINT-D)

KEYWORDS
POLYNOMIAL INTERPOLATION

AUTHOR
Huddleston, R. E., (SNLL)

DESCRIPTION
Written by Robert E. Huddleston, Sandia Laboratories, Livermore Abstract Subroutine POLINT is designed to produce the polynomial which interpolates the data (X(I),Y(I)), I=1,...,N. POLINT sets up information in the array C which can be used by subroutine POLYVL to evaluate the polynomial and its derivatives and by subroutine POLCOF to produce the coefficients. Formal Parameters N - the number of data points (N .GE. 1) X - the array of abscissas (all of which must be distinct) Y - the array of ordinates C - an array of information used by subroutines ******* Dimensioning Information ******* Arrays X,Y, and C must be dimensioned at least N in the calling program.

REFERENCES
L. F. Shampine, S. M. Davenport and R. E. Huddleston, Curve fitting by polynomials in one variable, Report SLA-74-0270, Sandia Laboratories, June 1974.

ROUTINES CALLED
XERMSG

REVISION HISTORY (YYMMDD)
740601 DATE WRITTEN
861211 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)
900315 CALLs to XERROR changed to CALLs to XERMSG. (THJ)
920501 Reformatted the REFERENCES section. (WRB)