On 12/24/2014 08:35 AM, Hans W Borchers wrote:
> No, You've got a typo. But, be careful fixing it,
> > it may eat up all your memory.
>
> A typo from copying. The problem is that first the memory error occurs
> and on second call it returns an empty error.
>
> julia> genprimes(1841378967856, 1850000000000)
> ERROR: MemoryError()
> in primescopy at
/home/hwb/.julia/v0.3/PrimeSieve/src/primesieve_c.jl:40
> in genprimes at
/home/hwb/.julia/v0.3/PrimeSieve/src/primesieve_c.jl:60
You are asking for a 2.5 GB array
julia> (countprimes(1841378967856, 1850000000000) * 8)/1e9
2.441857432
libprimesieve also needs temporary storage. I'm not sure how much. My
machine with 8GB
can do this.
> julia> genprimes(1841378967856, 1850000000000)
> 0-element Array{Int64,1}
>
> Well, I now see that you mention this in the "Bugs" section of the
README file.
Yes, I guess libprimesieve is left in a bad state after the memory error.
I wonder what the library means with tuplets. Is that documented somewhere?
You can find the definition in many places online. For instance, this
page is
linked from the libprimesieve website,
http://en.wikipedia.org/wiki/Prime_k-tuple
Look in the table "Named Patterns"
Don't worry. I took an old script of mine that computed only the first 10-20
> prime octetts (in R or Python) and converted it to Julia (utilizing
Julia's
> 'isprime'). During this night it computed *all* prime octetts up to
10^12 ,
> and there are hundreds of them, the last one being
>
> [99452940701, 99452940703, 99452940707, 99452940709,
> 99452940731, 99452940733, 99452940737, 99452940739]
>
That's not a prime octuplet. If you look around on the web, you'll find
the definition in several places, including on the wikipedia page linked
above.
It would be interesting to see it implemented.
--John
