Prime Numbers From List Function
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I have to make a function that gives all the prime numbers from a list [2:N]
The following steps is what I came up with:
1. First we make a list of number from 2 to 10. We start with a tester equal to 2, and remove all multiples of 2 from the list.
2. We look at the next remaining value, which is 3. Our tester now becomes equal to
3. We again remove al multiples of 3 from the list. 3. Again, we look at the next remaining value. tester is now 5, we remove al multiples of 5 (of which there are none).
4. We do this one last time with 7, of which there are also no multiples.
5. The final list contains all primes up to 10.
10 should be variable N and the range of numbers should be equal to 2:N
Could someone help me how I put this in function form?
So that the function getPrimeNumbers(N) returns all the prime values from the list [2:N]
All help is greatly appreciated!
1 Comment
Walter Roberson
on 2 Dec 2019
Search for Eratosthenes in MATLAB Answers. You will find numerous implementations.
Answers (1)
Catalytic Kys
on 2 Dec 2019
4 Comments
Steven Lord
on 2 Dec 2019
The primes function is implemented as a MATLAB function file (which is what I suspect you mean by "in code form".)
Walter Roberson
on 2 Dec 2019
That's odd. I just looked through https://www.mathworks.com/matlabcentral/answers/?term=tag%3A%22eratosthenes%22 and found full source code (and also a vectorized version.)
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