clc
clear all
yearn=[1 2 3 4 5 6]+1994
nasdaqv=[751 1052 1291 1570 2192 4069]
n=length(yearn)
p=polyfit(yearn,nasdaqv,n-1)
xi=yearn(1):(yearn(n)+3-yearn(1))/1000:yearn(n)+3;
yi=polyval(p,xi);
figure(5)
plot(yearn,nasdaqv,'o','MarkerSize',8)
hold on
plot(xi,yi,'LineWidth',3,'Color','Red')
hold off
xlabel('Year');
ylabel('NASDAQ');
title('Extrapolation is an Inexact Science');
legend('Data points','Polynomial Interpolant');
yearn =
1995 1996 1997 1998 1999 2000
nasdaqv =
751 1052 1291 1570 2192 4069
n =
6
Warning: Polynomial is badly conditioned. Add points with distinct X
values, reduce the degree of the polynomial, or try centering
and scaling as described in HELP POLYFIT.
p =
1.3791 -13753 5.4858e+007 -1.0941e+011 1.091e+014 -4.352e+016
