metode Gaus

n=4
p = [[ 2 1 1 3 ]' [ 3 -1 1 2 ]' [ -1 -1 2 1 ]' [ 1 2 1 -1 ]']
q = [ 5 6 1 0]'
r = p^(-1) * q
y=p\q

x=[0 0 0 0];
m21=p(2,1)/p(1,1)
m31=p(3,1)/p(1,1)
m41=p(4,1)/p(1,1)
p(2,1)=0;
p(3,1)=0;
p(4,1)=0;

p(2,2) = p(2,2)-m21*p(1,2)
p(2,3) = p(2,3)-m21*p(1,3)
p(2,4) = p(2,4)-m21*p(1,4)
q(2) = q(2)-m21*q(1)


p(3,2) = p(3,2)-m31*p(1,2)
p(3,3) = p(3,3)-m31*p(1,3)
p(3,4) = p(3,4)-m31*p(1,4)
q(3) = q(3)-m31*q(1)


p(4,2) = p(3,2)-m41*p(1,2)
p(4,3) = p(4,3)-m41*p(1,3)
p(4,4) = p(4,4)-m41*p(1,4)
q(4) = q(4)-m41*q(1)

m32=p(3,2)/p(2,2)
m42=p(4,2)/p(2,2)
p(3,2) =0;
p(4,2) =0;

p(3,3) = p(3,3)-m32*p(2,3)
p(3,4) = p(3,4)-m32*p(2,4)
q(3) = q(3)-m32*q(2)

p(4,3) = p(4,3)-m42*p(2,3)
p(4,4) = p(4,4)-m42*p(2,4)
q(4) = q(4)-m42*q(2)

m43=p(4,3)/p(3,3)
p(4,3)=0;

p(4,4) = p(4,4)-m43*p(3,4)
q(4) = q(4)-m43*q(3)

x(4) = q(4)/p(4,4)
x(3) = (q(3)-p(3,4)*x(4))/p(3,3)
x(2) = (q(2)-p(2,3)*x(3)-p(2,4)*x(4))/p(2,2)
x(1) = (q(1)-p(1,2)*x(2)-p(1,3)*x(3)-p(1,4)*x(4))/p(1,1)
x'