Borrar filtros
Borrar filtros

primes function

3 visualizaciones (últimos 30 días)
Sean Smith
Sean Smith el 18 de Sept. de 2011
Editada: Walter Roberson el 31 de En. de 2017
Is there a way to use the prime function to find the prime numbers between two numbers? I want to find the prime numbers between 20,000 and 10,000 and save that to a variable. primes(20000) gives me them all the way to zero and if i try to subtract primes(20000) and primes(10000) it won't let me because there not the same size. Any ideas? Thanks.
  1 comentario
Jack Garvey
Jack Garvey el 31 de En. de 2017
Editada: Walter Roberson el 31 de En. de 2017
1.) make array of range: range = [10000:1:20000]
2.) create logical array of (range) displaying which numbers are prime: isprime(range)
3.) find total amount of prime numbers within that range: number_of_primes = sum(isprime(range))
4.) i got the answer of 1033 prime numbers between 10K and 20K

Iniciar sesión para comentar.

Respuesta aceptada

Walter Roberson
Walter Roberson el 18 de Sept. de 2011
setdiff(primes(20000),primes(10000))

Más respuestas (1)

Andrei Bobrov
Andrei Bobrov el 18 de Sept. de 2011
k = 1e4:2e4;
out = k(isprime(k));
variant
prms = primes(20000);
out = prms(prms>=10000);

Categorías

Más información sobre Matrix Indexing en Help Center y File Exchange.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by