lineal

function l = lineal()
clc;
clear all;
cont = 10;
b = [67.052;68.008;69.803;72.024;73.400;72.063;74.669;74.487;74.065;76.777];
a = [1 1994; 1 1995; 1 1996; 1 1997; 1 1998; 1 1999; 1 2000; 1 2001; 1 2002; 1 2003];

at = transpose(a);

newa = mtimes(at, a);
newb = mtimes(at, b);

n = size(newa, 1);

for j = 1 : n - 1
    if abs(newa(j,j)) < eps; error('Pivote cero encontrado'); end;
    for i = j + 1 : n
        mult = newa(i,j)/newa(j,j);
        for k = j + 1 : n
            newa(i,k) = newa(i,k) - mult * newa(j,k);
        end
        newb(i) = newb(i) - mult * newb(j);
    end
end

for i = n : -1 : 1
    for j = i + 1 : n
        newb(i) = newb(i) - newa(i,j)*x(j);
    end
    x(i) = newb(i) / newa (i, i);
end

x = transpose(x);
ax = mtimes(a, x);
gamma = minus(b, ax);

ec = 0;
for i = 1 : size(gamma)
   ec = ec + (gamma(i))^2;
end

rmec = sqrt(ec/(cont));

for i = 1994 : 2003
   d(i - 1993) = x(1) + x(2)*i;
end

l = [d rmec];