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Search - "thousand plus plus"
"4096 bit ~ 96 hours is what he said.
IDK why, but when he took the challenge, he posted that it'd take 36 hours"
As @cbsa wrote, and nitwhiz wrote "but the statement was that op's i3 did it in 11 hours. So there must be a result already, which can be verified?"
I added time because I was in the middle of a port involving ArbFloat so I could get arbitrary precision. I had a crude desmos graph doing projections on what I'd already factored in order to get an idea of how long it'd take to do larger
@p100sch speculated on the walked back time, and overstating the rig capabilities. Instead I spent a lot of time trying to get it 'just-so'.
Worse, because I had to resort to "Decimal" in python (and am currently experimenting with the same in Julia), both of which are immutable types, the GC was taking > 25% of the cpu time.
Performancewise, the numbers I cited in the actual thread, as of this time:
largest product factored was 32bit, 1855526741 * 2163967087, took 1116.111s in python.
Julia build used a slightly different method, & managed to factor a 27 bit number, 103147223 * 88789957 in 20.9s,
but this wasn't typical.
What surprised me was the variability. One bit length could take 100s or a couple thousand seconds even, and a product that was 1-2 bits longer could return a result in under a minute, sometimes in seconds.
This started cropping up, ironically, right after I posted the thread, whats a man to do?
So I started trying a bunch of things, some of which worked. Shameless as I am, I accepted the challenge. Things weren't perfect but it was going well enough. At that point I hadn't slept in 30~ hours so when I thought I had it I let it run and went to bed. 5 AM comes, I check the program. Still calculating, and way overshot. Fuuuuuuccc...
So here we are now and it's say to safe the worlds not gonna burn if I explain it seeing as it doesn't work, or at least only some of the time.
Others people, much smarter than me, mentioned it may be a means of finding more secure pairs, and maybe so, I'm not familiar enough to know.
For everyone that followed, commented, those who contributed, even the doubters who kept a sanity check on this without whom this would have been an even bigger embarassement, and the people with their pins and tactical dots, thanks.
So here it is.
A few assumptions first.
Assuming p = the product,
a = some prime,
b = another prime,
and r = a/b (where a is smaller than b)
w = 1/sqrt(p)
(also experimented with w = 1/sqrt(p)*2 but I kept overshooting my a very small margin)
x = a/p
y = b/p
1. for every two numbers, there is a ratio (r) that you can search for among the decimals, starting at 1.0, counting down. You can use this to find the original factors e.x. p*r=n, p/n=m (assuming the product has only two factors), instead of having to do a sieve.
2. You don't need the first number you find to be the precise value of a factor (we're doing floating point math), a large subset of decimal values for the value of a or b will naturally 'fall' into the value of a (or b) + some fractional number, which is lost. Some of you will object, "But if thats wrong, your result will be wrong!" but hear me out.
3. You round for the first factor 'found', and from there, you take the result and do p/a to get b. If 'a' is actually a factor of p, then mod(b, 1) == 0, and then naturally, a*b SHOULD equal p.
If not, you throw out both numbers, rinse and repeat.
Now I knew this this could be faster. Realized the finer the representation, the less important the fractional digits further right in the number were, it was just a matter of how much precision I could AFFORD to lose and still get an accurate result for r*p=a.
Fast forward, lot of experimentation, was hitting a lot of worst case time complexities, where the most significant digits had a bunch of zeroes in front of them so starting at 1.0 was a no go in many situations. Started looking and realized
I didn't NEED the ratio of a/b, I just needed the ratio of a to p.
Intuitively it made sense, but starting at 1.0 was blowing up the calculation time, and this made it so much worse.
I realized if I could start at r=1/sqrt(p) instead, and that because of certain properties, the fractional result of this, r, would ALWAYS be 1. close to one of the factors fractional value of n/p, and 2. it looked like it was guaranteed that r=1/sqrt(p) would ALWAYS be less than at least one of the primes, putting a bound on worst case.
The final result in executable pseudo code (python lol) looks something like the above variables plus
while w >= 0.0:
if (p / round(w*p)) % 1 == 0:
x = round(w*p)
y = p / round(w*p)
if x*y == p:
w = w + i
Still working but if anyone sees obvious problems I'd LOVE to hear about it.39
I happen to be the only girl in my small dev team of 4 males plus me.
I'm freaking tired of hearing 'hey guys','how are you doing guys', 'what's the update guys' in every meeting/call when one of them is addressing the rest of us.
Yeah i know I/they can't do anything about it. I somehow grew numb to hearing it, but sometimes hearing it one thousand time in a single call is driving me crazy.
I once mentioned it to an a senior dev who happens to be the one using the g word the most during meeting.
Me: could you please stop saying guys all the time, I'm not a guy.
Him: what do you want me to say, 'hey guys and a girl?!'
Me: ... -_- (internally: seriously!!)
Boss: “Our ecommerce conversions in Google Analytics are less than the actual pace of orders.”
Me: “Nothing has changed in the tracking code or setup. It must be our goals setup which you have to have a Ph.D. to understand, plus whatever mood Google’s algorithms are in today.”
He’s not mad at me. We’re both just confused why Google AdWords, Analytics, and Tag Manager have to be so damn hard to get right. I’ve never been able to do it right. And most data is thrown out because people browse websites while logged into their Google Account, which makes their clickstream disappear and become unattributable because of understandable privacy policies. I don’t want my data tracked when I’m logged in either!
So now we have had to hire specialists at several thousand dollars per month to figure this out.
Woo time for a Chromebook rant against Samsung!
So they just 'revised' the Chromebook plus (Currently using v1 to write this) and I was intrigued because they ditched the Samsung made ARM chips for an intel CPU.... Buuuuuuuuuut... It's a fucking celeron... Of all fucking things to put in a half thousand dollar laptop, at least an m3 would be useful. Then I find out they are ditching the full metal body, it's heavier, thicker, same 3GB of RAM, ditching the 3:2 aspect ratio (Fucking why?!) and the 'upgraded' keyboard doesn't even have back lighting...
Ugh, makes me want a pixel book more, double the price and a million times the performance and quality -.-5