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Old 2010-08-04, 14:42   #408
science_man_88
 
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you all like starting arguments that never end and Pi I asked for your suggestions 2 of your posts back have a list ready yet ?
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Old 2010-08-04, 14:45   #409
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Quote:
Originally Posted by axn
What I mean is, the expected number of candidates to search for a prime is dependent only on the average candidate size and the sieve depth. For a factor-rich base, you would naturally start with less candidates (before sieving) as compared to a factor-deficient base.
Less candidates? Why is it that factor-rich bases can barely eliminate 9 in 10 in the sieving process, while prime or factor-deficient bases can easily eliminate 14 in 15 or 19 in 20?

Quote:
Originally Posted by axn
The numbers such as "1 in 7 candidates left" are irrelevant -- what is relevant is the aposteriori probability, after sieving, of a candidate yielding prime.
Irrelevant? They're irrelevant? Having fewer candidates = Better odds of finding a prime among the *remaining* candidates, as the obvious composites have all been eliminated.

Last fiddled with by 3.14159 on 2010-08-04 at 14:55
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Old 2010-08-04, 14:55   #410
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Quote:
Originally Posted by 3.14159 View Post
Less candidates? Why is it that factor-rich bases can barely eliminate 9 in 10 in the sieving process, while prime or factor-deficient bases can easily eliminate 14 in 15 or 19 in 20?



Irrelevant? They're irrelevant? Having fewer candidates = Better odds of finding a prime among the *remaining* candidates, as the obvious composites have all been eliminated.
yet you claim my idea is crap and it has some of that in it as well who falls now.
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Old 2010-08-04, 14:56   #411
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Quote:
Originally Posted by 3.14159 View Post
Why is it that factor-rich bases can barely eliminate 9 in 10 in the sieving process, while prime or factor-deficient bases can easily eliminate 14 in 15 or 19 in 20?
You should be able to answer this. (Also, the difference between the two should be larger, unless you're thinking of a less-rich version of "factor-rich" than I'm thinking of.)

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Having fewer candidates = Better odds of finding a prime among the *remaining* candidates, as the obvious composites have all been eliminated.
False.
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Old 2010-08-04, 14:58   #412
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Quote:
Originally Posted by CRGreathouse
False.
If you were assuming I was talking about changing the amount of primes found: Strawman. Never said anything about the amount of primes to be found. Point invalidated.

Else, disregard the above.

Last fiddled with by 3.14159 on 2010-08-04 at 15:00
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Old 2010-08-04, 15:06   #413
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Quote:
Originally Posted by CRGreathouse
I wasn't.
.. How would it be equally difficult to find a prime when there are less candidates to test? (Please, present us with your brilliant explanation.)

Last fiddled with by 3.14159 on 2010-08-04 at 15:11
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Old 2010-08-04, 15:09   #414
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Quote:
Originally Posted by 3.14159 View Post
.. How would it be equally difficult to find a prime when there are less candidates to test? (Please, present us with your brilliant explanation.)
Because there're less primes, too!

Read about Nash weight.
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Old 2010-08-04, 15:12   #415
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Quote:
Originally Posted by kar_bon
Because there're less primes, too!
In a fixed k-range, there are less primes after sieving? So, tell me, how does sieving accidentally kick out primes? X 2

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Old 2010-08-04, 15:15   #416
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Quote:
Originally Posted by 3.14159 View Post
In a fixed k-range, there are less primes after sieving? So, tell me, how does sieving accidentally kick out primes?
For someone who throws out strawmen arguments so often, I'd think you would be more careful about saying that sort of thing.
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Old 2010-08-04, 15:16   #417
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Quote:
Originally Posted by CRGreathouse
For someone who throws out strawmen arguments so often, I'd think you would be more careful about saying that sort of thing.
Strawmen? What strawmen did I make? I distorted nothing! He stated that in plain text!

Last fiddled with by 3.14159 on 2010-08-04 at 15:18
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Old 2010-08-04, 15:18   #418
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Quote:
Originally Posted by 3.14159 View Post
In a fixed k-range, there are less primes after sieving? So, tell me, how does sieving accidentally kick out primes? X 2
Less primes to find among the remaining candidates!

Example: k*2^n-1

n-range: 600000-1000000
sieved to p=26*10^12
k=337: 2618 candidates left
k=315: 32276 candidates left

Primes in that range found:
k=337: none
k=315: 3

BTW: k=337 got no prime for 172000<n<2600000!

Last fiddled with by kar_bon on 2010-08-04 at 15:20
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