# polint.f

          SUBROUTINE POLINT (N, X, Y, C)
    C***BEGIN PROLOGUE  POLINT
    C***PURPOSE  Produce the polynomial which interpolates a set of discrete
    C            data points.
    C***LIBRARY   SLATEC
    C***CATEGORY  E1B
    C***TYPE      SINGLE PRECISION (POLINT-S, DPLINT-D)
    C***KEYWORDS  POLYNOMIAL INTERPOLATION
    C***AUTHOR  Huddleston, R. E., (SNLL)
    C***DESCRIPTION
    C
    C     Written by Robert E. Huddleston, Sandia Laboratories, Livermore
    C
    C     Abstract
    C        Subroutine POLINT is designed to produce the polynomial which
    C     interpolates the data  (X(I),Y(I)), I=1,...,N.  POLINT sets up
    C     information in the array C which can be used by subroutine POLYVL
    C     to evaluate the polynomial and its derivatives and by subroutine
    C     POLCOF to produce the coefficients.
    C
    C     Formal Parameters
    C     N  - the number of data points  (N .GE. 1)
    C     X  - the array of abscissas (all of which must be distinct)
    C     Y  - the array of ordinates
    C     C  - an array of information used by subroutines
    C     *******  Dimensioning Information  *******
    C     Arrays X,Y, and C must be dimensioned at least N in the calling
    C     program.
    C
    C***REFERENCES  L. F. Shampine, S. M. Davenport and R. E. Huddleston,
    C                 Curve fitting by polynomials in one variable, Report
    C                 SLA-74-0270, Sandia Laboratories, June 1974.
    C***ROUTINES CALLED  XERMSG
    C***REVISION HISTORY  (YYMMDD)
    C   740601  DATE WRITTEN
    C   861211  REVISION DATE from Version 3.2
    C   891214  Prologue converted to Version 4.0 format.  (BAB)
    C   900315  CALLs to XERROR changed to CALLs to XERMSG.  (THJ)
    C   920501  Reformatted the REFERENCES section.  (WRB)
    C***END PROLOGUE  POLINT