e01bef

e01bef © Numerical Algorithms Group, 2002.

Purpose

E01BEF Interpolating functions, monotonicity-preserving, piecewise cubic Hermite, one variable

Synopsis

[d,ifail] = e01bef(x,f<,ifail>)

Description

 
 This routine estimates first derivatives at the set of data 
 points (x ,f ), for r=1,2,...,n, which determine a piecewise 
          r  r                                               
 cubic Hermite interpolant to the data, that preserves 
 monotonicity over ranges where the data points are monotonic. If 
 the data points are only piecewise monotonic, the interpolant 
 will have an extremum at each point where monotonicity switches 
 direction. 
 
 Values of the computed interpolant, and of its first derivative 
 and definite integral, can subsequently be computed by calling 
 E01BFF, E01BGF and E01BHF.

Parameters

e01bef

Required Input Arguments:

x (:)                                 real
f (:)                                 real

Optional Input Arguments:                       <Default>

ifail                                 integer  -1

Output Arguments:

d (:)                                 real
ifail                                 integer