What is wrong with my code?

Hi, im trying to create a function which returns every prime number between 1 and 'N' Number using other two fuction which works fine.

This are the two function:

function [q] = Elimina_Multiplos(s,N) %This function eliminates multiples of N, except N and 1
    q = s; 
    q(~mod(q,N) & q ~= N & N ~= 1) = [];
end

and

function [ A ] = Numeros_Iguales( a,b ) %This function looks fot similar numbers between two arrays, and returns only such numbers
    A = [];
    for n = 1:length (a)
        for m = 1:length(b)
               if a(n) == b(m)
                   A = [A,n]; 
               end;
        end;
    end;
end

AND THIS IS THE FUNCTION which returns only the primes numbers between 1 and N number.

function [p] = Primos(N)
    q = [];
    r = [];
    p = 1:10;
    for x = 1:N
        q = Elimina_Multiplos(1:N,x);
        r = Numeros_Iguales(p,q);
        p = r;
    end;
end

It seems to be ok, but when I evaluate, for example, from 1 to 10 (N=10) it should return 1 2 3 5 7 but instead this happens: 1 2 3 4 5

[Walter Roberson]

I recommend you rewrite the second function in terms of intersect()

[David Goodmanson]

[1] take a look at the statement A = [A,n].

[2] the restriction of p to <= 10 seems a bit artificial since it limits the number of primes you can get on output.

Answer 1

[David Goodmanson]

(I guess my previous comment might be considered an answer). Take a look at the statement A = [A, n] which is not what you intended, and after you correct that it works great. However, restricting p to <=10 (something you did temporarily?) limits the number of primes you can produce to those <= 7. Also, it's kind of pedantic to bring it up, but 1 is not a prime.