primes function
3 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
Sean Smith
am 18 Sep. 2011
Bearbeitet: Walter Roberson
am 31 Jan. 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 Kommentar
Jack Garvey
am 31 Jan. 2017
Bearbeitet: Walter Roberson
am 31 Jan. 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
Akzeptierte Antwort
Weitere Antworten (1)
Andrei Bobrov
am 18 Sep. 2011
k = 1e4:2e4;
out = k(isprime(k));
variant
prms = primes(20000);
out = prms(prms>=10000);
0 Kommentare
Siehe auch
Kategorien
Mehr zu Matrix Indexing finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!