Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#51 2012-04-11 03:18:29

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,522

Re: The RRA

Why didn't it output right to me,then?


“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

Offline

#52 2012-04-11 03:30:10

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,478

Re: The RRA

You had a denominator that was too large.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Online

#53 2012-04-11 10:55:56

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,478

Re: The RRA

Estimate the following sum for a PSLQ to 16 digits of precision. I would like to only sum 20 or so terms. Develope a new series that converges that fast.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Online

#54 2012-07-11 16:23:17

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,522

Re: The RRA

Hi bobbym

The number of terms needed doesn't seem to be going down.


“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

Offline

#55 2012-07-11 22:07:26

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,478

Re: The RRA

Hi;

I am not following you. What are you getting?


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Online

#56 2012-07-12 02:20:24

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,522

Re: The RRA

When I apply the RRA it doesn't shrink down the number of terms needed.


“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

Offline

#57 2012-07-12 02:29:48

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,478

Re: The RRA

Hi;

After 8 iterations of the algorithm I get:

That is quite close for only summing 19 terms!


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Online

#58 2012-07-12 02:35:08

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,522

Re: The RRA

Eight iterations! I do not have that capability by hand and I don't yet have a program to do it for me.


“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

Offline

#59 2012-07-12 05:30:15

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,478

Re: The RRA

Point is, it is converging. Looking the bottom series of all positive terms. Do you not see convergence? How many iterations did you do?


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Online

#60 2012-07-12 06:00:22

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,522

Re: The RRA

I see the convergence, but I applied the RRA only 2 times.


“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

Offline

#61 2012-07-12 06:05:16

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,478

Re: The RRA

So you got 1 /10 + 1 / 45? Isn't that close to the answer?


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Online

#62 2012-07-12 06:09:35

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,522

Re: The RRA

It is. But the sum we get doesn't converge as fast as we'd like it to.


“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

Offline

#63 2012-07-12 06:14:44

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,478

Re: The RRA

Whoa! Do you know many terms you would need of the original series to get the accuracy you have got
from just 2 iterations?


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Online

#64 2012-07-20 13:26:52

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,522

Re: The RRA

bobbym wrote:

Whoa! Do you know many terms you would need of the original series to get the accuracy you have got
from just 2 iterations?

No. How many?


“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

Offline

#65 2012-07-20 14:59:50

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,478

Re: The RRA

You have forgotten how to get it? Or you never learned it from our discussions of Taylor series?
Or you are not the same guy?


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Online

#66 2012-07-20 15:26:08

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,522

Re: The RRA

I am the same guy, but I do not like typing math expressions into Wolfram while on the phone. I will do it as soon as I get to my laptop.


“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

Offline

#67 2012-07-20 15:28:07

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,478

Re: The RRA

You will first need to ascertain the accuracy of the answer we are getting without knowing the real answer!


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Online

#68 2012-07-20 15:34:57

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,522

Re: The RRA

Why do that? I just set the tail equal to the desired accuracy and solve it in WA. That is the least I could remember.

While I was in the mountains, I managed once to get a wireless connection and see the latest baffler. When I realized what the first differences are I needed to get the first 50 or so digits of pi. I wanted to use the Leibniz formula, but I remembered that it converges slowly so I applied RRA. I got another series that is the result of applying the RRA infinitely many times which involved a double factorial, but the new series wasn't particularly fast either. My confidence in the RRA was then shaken. But at least I tried to use it.


“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

Offline

#69 2012-07-20 15:36:45

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,478

Re: The RRA

You are confusing the methods of numerical mathematics with the methods you  have been taught. You are confusing the discrete with the continuous.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Online

#70 2012-07-20 15:43:02

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,522

Re: The RRA

Which part of my post are you referring to?


“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

Offline

#71 2012-07-20 15:44:03

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,478

Re: The RRA

Has to be the second paragraph. The first is an error.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Online

#72 2012-07-20 15:47:49

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,522

Re: The RRA

What is the part I have done wrong while calculating pi?

And why is the first part an error?


“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

Offline

#73 2012-07-20 15:50:02

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,478

Re: The RRA

The first sentence is clearly wrong.

The second paragraph violates the properties that are inherent in the way numerical math is done.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Online

#74 2012-07-20 15:54:01

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,522

Re: The RRA

Yeah, not the whole tail. I set the absolute value of the general term to the 0.5*10**number of accurate digits required and solve it to get how many terms I need to sum.

What properties?


“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

Offline

#75 2012-07-20 15:56:21

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,478

Re: The RRA

How about showing me what you call a Leibniz series.


In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.

Online

Board footer

Powered by FluxBB