Math Is Fun Forum

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: Is this cool with you?

Hi bobbym,

Yes, it's intensive for big numbers.
I think it might already be out there somewhere, but don't know what words to search for!

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Is this cool with you?

Hi gAr;

It is definitely out there! The wikipedia page mentions a journal article written by Wendl. This paper deals with what you are doing. I have googled for it but no luck!

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: Is this cool with you?

Hi,

Oh, okay.
Is that exactly the one we are dealing with?

I despise it when I see "purchase"! Why do they need money for giving some information?!

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Is this cool with you?

Hi gAr;

I think it covers it. For right now we will go with what you did.
It looks okay to me.

I hate that too. They try to sell articles that are 25 years old.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: Is this cool with you?

Hi,

Okay.
You think we can extend the formula to 'n' persons? I believe so.

Last edited by gAr (2011-08-25 03:24:15)

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Is this cool with you?

Hi gAr;

I think you did that in post #976. It will be slow but it will work!
If something comes up that is faster that will be good, if not...

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: Is this cool with you?

Hi bobbym,

Okay.

How about this approximation?

I'll take a short break, see you later.

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Is this cool with you?

Hi gAr;

Yikes! I will need to have some data to test that on. Right now I have 2 examples.

Okay, see you in a bit.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: Is this cool with you?

Hi bobbym,

I checked for a few values.
It gets good approximation when mn < d.
Perhaps we can have something similar for more people.

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Is this cool with you?

Hi gAr;

mn < d? Why should that be a condition? It is not mentioned in
the original birthday sum.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: Is this cool with you?

Hi,

Not a condition for the birthday problem, I thought a good approximation can be got by that condition.
Anyway, checking for a few more values I think that doesn't matter.

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Is this cool with you?

Hi gAr;

For m = 4 and n = 4 and d = 32

While the true answer is .397533

That is not close enough.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: Is this cool with you?

Hi bobbym,

The answer I'm getting is 0.602466572920093
and the approximation is 0.606530659712633

A simulation gets 0.60342 for 100000 trials

Last edited by gAr (2011-08-25 05:11:05)

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Is this cool with you?

Hi gAr;

I see it now. I forgot to subtract the series answer from one.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: Is this cool with you?

Hi,

Oh, okay.

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Is this cool with you?

Hi;

I am trying it and it is pretty good. Better than the approximation they gave in the PDF, post #975.

How do you derive it?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: Is this cool with you?

Hi bobbym,

The root of the approximation is the one you wrote there!

Then, for sufficiently large d:

By the way, what was the PDF you mentioned, a file? I couldn't see any link.

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Is this cool with you?

Hi gAr;

http://www.hautakorpi.com/scripts/downl … ctype=docs

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: Is this cool with you?

Hi,

Thanks for the link.
If there was a derivation of the approximation, could've thought of a generalization!

Anyway, I saw it's copyrighted to IEEE and not the authors.
Is that the case with every journal?

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Is this cool with you?

I am kind of tainted on journals. I agree with D. Zeilberger.

About the IEEE, I do not know. My uncle used to say that
the day would come that they would charge us to breathe.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: Is this cool with you?

Hmmm, okay.
Actually, I have never read any journal, except the pieces which are scattered around the internet.
If I ever find anything new, I'll publish it only on forums! Off with those journo nitwits!

Your uncle is right!

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: Is this cool with you?

Actually,I have never understood what you two wrote here.
If i ever do it will be a miracle.

---

“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Is this cool with you?

Hi gAr;

You might want to publish someday.  There are decent places on the internet where they do not rip your stuff off and say they did it!

Hi anonimnystefy;

Yes, it will be a miracle. Miracles happen all the time and sooner than you think!

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: Is this cool with you?

ok so you agree that if i ever understand any of this stuff it will be a miracle?

anyway,based on what i have shown on this forum what would you suggest i start doing and learning?

---

“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

gAr

Member

Registered: 2011-01-09

Posts: 3,482

Re: Is this cool with you?

Hi bobbym,

Okay, let me see if that time comes. Or maybe I'll just maintain a dairy!

Hi anonimnystefy,

You'll understand. Just read the discussion and follow the links / search for the unknown, that's all !
It's a miracle for me too.
Just a few hours ago, I had no idea how to approach, even after trying hours at a stretch.
I'd recommend g.f's first, definitely the most useful stuff out there!

---

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense"  - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."