%MATLAB script for testing the function CHEB for example 6.10 on page 258 of conte/deboor
% as test we compute and plot the Chebyshev polynomials of degree <=4
% using the fact that CHEB has been written to handle simultaneous evaluation
% at all the entries of the input vector X .
%
%  Reference:
%
%    Samuel Conte, Carl de Boor,
%    Elementary Numerical Analysis,
%    Third Edition,
%    SIAM, 2017,
%    ISBN: 978-1-611975-19-2.
%
X = -1:.02:1;
c = eye(5);
plot([-1.2 1.2 1.2 -1.2,-1.2],[-1.2 -1.2 1.2 1.2 -1.2]), hold on
for j=1:5
   plot(X, CHEB(c(:,j),X))
end
axis off
title('The Chebyshev polynomials of degree < 5')
hold off

