I can`t solwe gauss elimination method

function [ ret ] = EliminacjaGaussaWSEI()
format short
clc
clear
[A,b,n]=macierz;
m= wprzod (A,b,n);
m= eliminacja (m,n);
x= odwrotne(m,n);
disp(x)
endfunction
function [ A,b,n] = macierz ()
A=[ -3 6 -1 -2; -3 3 -3 1; -1.5 4.5 -2.5 -0.5; 0 1.5 -0.5 -3.5];
n=4;
b=[10; 16; 13; 17];
endfunction

function [ a] = eliminacja (a,n)
	for k = 1: n-1
		for i = k+1 : n
			m(i,k)= a(i,k)/a(k,k);
			for j = k:n+1
				a(i,j)= a(i,j)-(m(i,k)*a(k,j));
			end
		end
	end
endfunction
function [ A] = wprzod (A,b,n)
for c = 1 : n
	A(c,n+1)=b(c);
end
endfunction
function [ x ] = odwrotne (m,n)
x(n)= m(n, n+1)/m(n,n);
for i=n-1:-1:1
	acum = 0; 
	for p = i+1:n
		acum = acum + (m(i,p)*x(p));
	end
	x(i)= (m(i, n + 1) - acum)/m(i, i);
end
endfunction

Answer 1

[Jan]

I've simplified the code and converted it from Octave to Matlab:

A = [ -3 6 -1 -2; -3 3 -3 1; -1.5 4.5 -2.5 -0.5; 0 1.5 -0.5 -3.5];
n = 4;
b = [10; 16; 13; 17];

m = [A, b];
m = eliminacja(m, n);
x = odwrotne(m, n);
disp(x)

   -2.2963   -2.2407   -6.8889   -4.8333

A \ b

ans = 4×1

-2.2963 -2.2407 -6.8889 -4.8333

function a = eliminacja(a,n)
   for k = 1:n-1
      for i = k+1:n
         m(i,k) = a(i,k)/a(k,k);
         for j = k:n+1
            a(i,j) = a(i,j)-(m(i,k)*a(k,j));
         end
      end
   end
end

function x = odwrotne (m,n)
x(n) = m(n, n+1) / m(n,n);
for i = n-1:-1:1
   acum = 0; 
   for p = i+1:n
      acum = acum + (m(i, p) * x(p));
   end
   x(i)= (m(i, n + 1) - acum)/m(i, i);
end
end

It runs fine and replies the same output as A\b. So what do you consider as a problem? Maybe the missing definition of the output "rec"? Then replace:

function [ ret ] = EliminacjaGaussaWSEI()

by

function x = EliminacjaGaussaWSEI()