0
$\begingroup$

How would I find the total number of prime numbers between 1 million and 2 million on MATLAB. I have the code for displaying every prime number between 2 integers being:

n = firstnumber : secondnumber;
p = isprime(n);
n(p)     %displays the primes

But how would I code it so it gives me a total number of primes between 2 numbers.

Any help will be appreciated.

  • 0
    From `p`, you only need `sum(p)` or `nnz(p)` – 2017-01-23

1 Answers 1

0

Not necessarily the most efficient way of doing it but for your numbers it's still very fast:

p = primes(secondnumber);
n = length(find(p>=firstnumber));

About 20ms here.