Math Is Fun Forum

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: π

I am here and waiting.

---

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.

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,996

Website

Re: π

>>> def pi(n):
	s = Decimal()
	for i in xrange(0,n+1):
		s += ((-1**i)*((Decimal(1)/Decimal(5))**(2*i+1)))/((2*i)+1)
	s *= 16
	for i in xrange(0,n+1):
		s -= 4*(((-1**i)*((Decimal(1)/Decimal(239))**(2*i+1)))/((2*i)+1))
	print s

	
>>> pi(10)
-3.226984365524281777452846574

What is wrong?

---

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: π

Hi;

>>> def pi(n):
    s = Decimal()
    for i in xrange(0,n+1):
        s += ((-1**i)*((Decimal(1)/Decimal(5))**(2*i+1)))/((2*i)+1)
    s *= 16

Please run that and post the answer. Then run the second piece and post that answer.

---

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.

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,996

Website

Re: π

>>> def pi(n):
    s = Decimal()
    for i in xrange(0,n+1):
        s += ((-1**i)*((Decimal(1)/Decimal(5))**(2*i+1)))/((2*i)+1)
    s *= 16
    print s

    
>>> pi(10)
-3.243720864865314995238473720

---

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: π

Put a parentheses around that -1.

---

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.

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,996

Website

Re: π

>>> def pi(n):
	s = Decimal()
	for i in xrange(0,n+1):
		s += (((-1)**i)*((Decimal(1)/Decimal(5))**(2*i+1)))/((2*i)+1)
	s *= 16
	for i in xrange(0,n+1):
		s -= 4*((((-1)**i)*((Decimal(1)/Decimal(239))**(2*i+1)))/((2*i)+1))
	print s

	
>>> pi(10)
3.141592653589793294747374859
>>> pi(100)
3.141592653589793238462643384

I'm so stupid.

My apologies for being late to reply. I had been dining.

---

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: π

Hi;

π = 3.14159265358979323846264338328...

So you see you have lots of digits from only 100 iterations.

---

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.

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,996

Website

Re: π

Yup

---

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,996

Website

Re: π

>>> getcontext().prec = 100
>>> pi(100)
3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342117064
>>> pi(10000)
3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342117064

So, already a lot

---

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: π

That particular formula was used when Shanks calculated pi to 707 places without an electronic computer. He used a human one. But there was a mistake on the 527 digits so all the rest from there on are wrong. Still, it was a record that lasted until modern times and electronic computers.

---

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.

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,996

Website

Re: π

Did he use himself?

---

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: π

A guy called Dase was used. He was an idiot savant capable of multiplying two 100 digit numbers in his head in 5 or 6 hours. He did all the computation.

---

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.

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,996

Website

Re: π

isn't 5 or 6 hours a lot?

---

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: π

Yes, but it is a mistake. Shanks did the calculation in 1873 and Dase was dead by 1861 so he must have used someone else that was similar. Also, it took Dase 8 hours to multiply two 100 digit numbers.

---

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.

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,996

Website

Re: π

How were such guys found/developed?

---

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: π

[deleted by administrator]

---

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.

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,996

Website

Re: π

Do we really need that ability?

---

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: π

[administrative delete]

---

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.

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,996

Website

Re: π

Why should they try to hide it? Who are they, by the way?

---

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: π

The same that we discussed in the PM, among others.
[administrative delete]

---

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.

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,996

Website

Re: π

Who are special then?

Those people are power greedy ones. What can happen to them if people compute faster?

Just because someone is able to compute very fast, that does not mean that he is very wise. Mere computation won't take mathematics farther.

---

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: π

Computation is a very important part of math. A point I have been trying to make since I got here. It represents a new way of thinking about things.

Mere computation won't take mathematics farther.

That is the end result of what I have been saying. Nothing could be further from the truth.

But it is only the tip of the iceberg when we talk about the hidden capabilities of a human being.

---

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.

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,996

Website

Re: π

Which people are special then?

Why did you have to delete those comm?ents?

---

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: π

They are about things that I do not wish the entire internet to see.

Special is the wrong word. Let's just say those are common abilities.

---

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.

Agnishom

Real Member

From: Riemann Sphere

Registered: 2011-01-29

Posts: 24,996

Website

Re: π

Yes, but what is special, then?

---

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
I'm not crazy, my mother had me tested.