% cheb_interp_.m
% need cheb_mat.m
function main(f,a,b,deg)
f = fcnchk(f); % make f as a function
xx = linspace(a,b,10*deg+1);
pxx = f(xx); % original function to find
% polynomial interpolation with equispaced data
xe = linspace(a,b,deg+1);
ye = f(xe);
pe = polyfit(xe,ye,deg);
pex = polyval(pe,xx);
% Chebyshev polynomial interpolation with Chebyshev Gauss points
[D,xg,we] = cheb_mat(deg+1,1);
% D = Diff matrix, xg = gauss points in [-1,1], we = weights
xg = a + (b-a)*(xg+1)/2; % gauss points in [a,b]
yg = f(xg);
pg = polyfit(xg,yg,deg);
pgx = polyval(pg,xx);
%plot(xe,ye,'o',xx,pxx,'b-',xx,pex,'m-.')
%pause
%plot(xg,yg,'o',xx,pxx,'b-',xx,pgx,'m-')
%pause
plot(xe,ye,'m*',xg,yg,'ro',xx,pxx,'b-',xx,pex,'m-',xx,pgx,'r-')
title('Interpolations : Magenta(equispace), Red(Cheby Gauss pts) ')
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이름검색
수치해석특강 성적
수치해석 및 실습 성적
