Aproximare MCMMP
Recensamantul SUA
Datele de mai jos au fost inregistrate de US Census intre 1900 si 2010
%CENSUS - example with census data
% exponetial fit
%data
y = [ 75.995 91.972 105.711 123.203 131.669 150.697 ...
179.323 203.212 226.505 249.633 281.422 308.786]';
t = (1900:10:2010)'; % census years
Dorim sa modelam datele si sa facem predictii pentru anii 1975 si 2015
x = (1890:1:2019)'; % evaluation years
w = [1975,2015]; % prediction year
Vom modela datele printr-un model exponential
Fitting exponential
coeficientii
cs=polyfit(t,log(y),1);
K=exp(cs(2))
lambda=cs(1)
predictiile:
fm=@(t) K*exp(lambda*t);
zs=fm(x);
est=fm(w);
Reprezentarea grafica
plot(t,y,'o',x,zs,'-',w,est,'*')
for i=1:length(w)
text(w(i),est(i)-20,num2str(est(i)))
end
title('U.S. Population', 'FontSize', 14)
xlabel('year', 'FontSize', 12)
ylabel('Millions', 'FontSize', 12)