Copii

copii = dlmread('copii.txt');
n = rows(copii);
inaltime = copii(:,1);
greutate = copii(:,2);
varsta = copii(:,3);
#subplot(1,1,1);

plot(inaltime,greutate,'ro');
title('Dependenta dintre inaltime si greutate');
xlabel('Inaltime [m]');
ylabel('Greutate [kg]');
printf('coeficientul de corelatie intre inaltime si greutate : %f \n',corr(inaltime,greutate));

x = inaltime;
y = greutate;
beta1 = (sum(x)*sum(y)-n*sum(x.*y))/(sum(x)*sum(x)-n*sum(x.*x));
beta0 = (sum(x)*sum(x.*y)-sum(x.*x)*sum(y))/(sum(x)*sum(x)-n*sum(x.*x));

printf('\n Coef. de regresit: %f\n',beta1);
printf('\n Interceptia: %f\n',beta0);
hold on;
t = linspace(1.1,2.0,5);
title('Regresia liniara simpla');
plot(t,beta1*t+beta0,'-r');
grid;