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#26 2012-03-25 07:41:33

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,526

Re: Crazy Fractions!!!

i think so.actually i just saw that it is actually an installation thingy.i don't have it installed yet sad


“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

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#27 2012-03-25 07:43:47

bobbym
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From: Bumpkinland
Registered: 2009-04-12
Posts: 86,719

Re: Crazy Fractions!!!

Oh boy! That means you have no experience with the CAS inside. That will make your job 10 times harder.


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.

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#28 2012-03-25 07:53:22

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,526

Re: Crazy Fractions!!!

sad


“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

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#29 2012-03-25 08:20:48

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,719

Re: Crazy Fractions!!!

Okay, the first problem looks like this.

The city of Albany is experiencing a movement of its population. At present 85% of the population lives in the city and 15% in the suburbs. Each year 7% of the population moves to the suburbs and 1% of the suburb population move back to the city. Assuming the population of the city + the suburbs stays constant. After 5 years what percentage of people will live in the city?

You can work on that problem on your own before I show you how to do it with a Markov chain.

A couple of questions:

1)Have you heard of the Feynmann story of why he was such a good problem solver?

2)What do you think of back engineering as a method of problem solving?

3)Have you seen gAr and my work on these Markov chains?

I have a long distance call coming in so I will be busy for a while.


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.

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#30 2012-03-25 08:38:57

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,526

Re: Crazy Fractions!!!

1)No.

2)It's nice and useful.

3)Yes,but i have never understood it. sad


“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

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#31 2012-03-25 08:58:44

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,719

Re: Crazy Fractions!!!


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

#32 2012-03-25 09:56:15

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,526

Re: Crazy Fractions!!!

Nice text.Very true.


“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

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#33 2012-03-25 11:16:48

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,719

Re: Crazy Fractions!!!

Do you have an answer to the problem? By any method?


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

#34 2012-03-25 12:09:57

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 3,848

Re: Crazy Fractions!!!

Hi Bobby,


"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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#35 2012-03-25 12:23:36

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,719

Re: Crazy Fractions!!!

Hi phrontister;

It wasn't actually a question I was posing. It is part of a lesson on Markov chains for anonimnystefy. But that is okay that you answered it, I will check your 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

#36 2012-03-25 12:30:02

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 15,526

Re: Crazy Fractions!!!

Hi bobbym

I would just calculate it by hand and get the answer, but it is too long so let's pretend that I got it correctly.


“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

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#37 2012-03-25 12:33:35

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,719

Re: Crazy Fractions!!!

Hi All;

Sorry for the delay, I am having an emergency here and will be busy. Sorry for the problem.


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

#38 2012-03-25 12:35:58

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 3,848

Re: Crazy Fractions!!!

Ok, Bobby. I'm off to work now...I'll check in later.


"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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#39 2012-03-25 14:29:25

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,719

Re: Crazy Fractions!!!

Hi phrontister;


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

#40 2012-03-25 14:31:24

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,719

Re: Crazy Fractions!!!

Hi anonimnystefy;

It would have been better if you would have worked through the problem one time to see what is involved but I will go ahead with the example.

This is the initial vector:

This is the transition matrix. Notice how all the rows sum to 1. This means the matrix is a stochastic matrix.

The answer is:

So after 5 years 60% of the population still lives in the city.


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

#41 2012-03-25 15:13:44

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 3,848

Re: Crazy Fractions!!!

Hi Bobby,

Last edited by phrontister (2012-03-25 19:39:47)


"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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#42 2012-03-25 19:49:00

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 86,719

Re: Crazy Fractions!!!

Hi phrontister;


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

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