data = load('weather.ascii');

x = data(:,2);
y = data(:,3);

p = polyfit(x,y,1)

plot(x,y, '.')
grid

kov = cov(x,y)
kor = corr(x,y)

hold on;
plot(x, p(1).*x + p(2), '-');
legend('Data', ['Line', char(225), 'rn', char(237), ' regrese']);
title('Zavislost teploty na geopotencialni vysce')
xlabel('Geopotencialni vyska [m]')
ylabel(['Teplota [' char(176) 'C]'])
text (7200, -18, ["y = ",num2str(p(1)), "*x + ", num2str(p(2))]);
text (1000, -45, ["korelace = ",num2str(kor)]);
text (1000, -50, ["kovariance = ",num2str(kov)]);
hold off