Matlab code for Eratosthenes

I wrote a code for the sieve of Eratosthenes, but the grader was not satisfied with my code. I'm not sure what I did wrong to his eyes. Any ideas? Please and thank you!

function p = prime_seive(n)

p = [0 2:n];   
for k = 2:sqrt(n)
    
if p(k)   
p(k^2:k:n) = 0;

end
end
p = p(p ~= 0);
end

[Stephen23]

Which refinement of the sieve are you supposed to implement?

[Aaron Millan]

I was given a pseudocode to work with, and in that code was a "for loop" where

k = 2:sqrt(n), and if pk was not zero, then we set p(j) equal to zero where j = k^2, k^2 +k, k^2 +2k...n

[Stephen23]

Did the grader give any hints or feedback? Which cases failed?

Have you checked the requirements for the vector orientation?

[Aaron Millan]

Thankfully, they didn't ask for any specific vector orientation. I can't post a picture of the instructions here due to copyright, but let me wite out the two theorems they wanted included:

1) if c is not divisible by any number less than c, then c is prime

2) If c is not divisible by any interger between 2 and sqrt(n), then c is prime

Maybe he was just being a stickler for the pervious parts.

[Krystian]

maybe the wrong spelling of "sieve" in the function's name?

Answer 1

[Jan]

The code works fine and replies the correct values for:

[], 1, 2, 3, 10, 100, 200

Maybe inputs like NaN or vectors should be caught also? Is a column vector expected as output?

[Aaron Millan]

I actually just needed an array. this grader has given me issues before, though. Thank you for checking my code!