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## #101 2012-04-30 01:45:25

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Generating Functions

Procedural form?

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.

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## #102 2012-04-30 01:48:35

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Generating Functions

Loops and such.

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.

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## #103 2012-04-30 01:50:12

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Generating Functions

There is no other way.At least not that I know of.But Maxima allows while loops.

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.

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## #104 2012-04-30 01:51:23

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Generating Functions

While loops are procedural. Why are you not using math commands to do math?

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.

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## #105 2012-04-30 01:58:25

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Generating Functions

What would you to sum those terms 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
The knowledge of some things as a function of age is a delta function.

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## #106 2012-04-30 02:03:45

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Generating Functions

Sum[x^k,k,1,6] yields

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.

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## #107 2012-04-30 02:08:53

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Generating Functions

``````CombGF(list) := block([i, a, m, s],
i = 1,
m = 1,
while i <= length(list) do
[
a = get(list,i),
s=sum(x^k/k!,k,1,i),
m = m * s,
delete(a,list,1),
i = i + 1
],
print(m)
);``````

Last edited by anonimnystefy (2012-04-30 02:11:39)

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.

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## #108 2012-04-30 02:16:17

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Generating Functions

You do not need the while loop and you are jumping ahead. Let's get the OGF's down first.

To have the probability gf for 2 die:

Sum[x^k/6,k,1,6]^2 yields

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.

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## #109 2012-04-30 02:18:58

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Generating Functions

I want the function to do everything for me.I just have to input 6,6 instead of just 6 to get probability for 2 dice.

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.

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## #110 2012-04-30 02:25:02

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Generating Functions

I want the function to do everything for me.I just have to input 6,6 instead of just 6 to get probability for 2 dice.

That is overkill. You make functions that do the minimum and use other commands on them. You do not try to make functions to do everything.

You make a function that inputs the parameters you need and then you use the series inside the function.

Here is pseudocode:

gf(a,b,d)

Begin:

Sum[x^k/d,k,a,b]

End:

Now when you call gf(1,6,6) you get:

Congratulations you just threw a die!

To throw 2 you just go

gf(1,6,6)^2

Simple, no need to make a function throw  n die when you just have to square or cube or raise to the 10th power...

I want you to work on creating a function gf that inputs the 3 parameters as I have indicated.

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.

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## #111 2012-04-30 03:51:13

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Generating Functions

This code both compiles and runs,but doesn't give a good output:

``````CombGF(list) := block([i, a, m, s],
i : 1,
m : 1,
while i <= length(list) do
[
a : first(list),
print(a),
s : sum(x^k, k, 0, a),
m : m * s,
list:rest(list),
i : i + 1
],
print(m)
);``````

and the output for:

list:[1,1,2,3];
CombGF(list);

is:

[1,1,2,3]
1
1
(x+1)^2

Last edited by anonimnystefy (2012-04-30 03:51:46)

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.

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## #112 2012-04-30 04:08:14

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Generating Functions

Done it! Could you do a little test on the code:

Exp GF:

``````CombEGF(list) := block([i, a, m, s],
i : 1,
m : 1,
l : length(list),
while i <= l do
[
a : first(list),
s : sum(x^k/k!, k, 0, a),
m : m * s,
list : rest(list),
i : i + 1
],
m
);

Ordinary GF:

``````CombOGF(list) := block([i, a, m, s],
i : 1,
m : 1,
l : length(list),
while i <= l do
[
a : first(list),
s : sum(x^k, k, 0, a),
m : m * s,
list : rest(list),
i : i + 1
],
m
);

The coefficient of OGF:

``````OGFcoeff(list,n) := ratcoeff(CombOGF(list),x^n);

The coefficient of EGF:

``````EGFcoeff(list,n) := ratcoeff(CombEGF(list),x^n)*n!;

Notice that I multiply by n! in the EGFcoeff function to get the final result immediately.

Last edited by anonimnystefy (2012-04-30 04:50:58)

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.

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## #113 2012-04-30 05:19:51

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Generating Functions

Hi;

Please look at my hidden text message in post 110.

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.

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## #114 2012-04-30 05:24:18

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Generating Functions

I did even more than that.The function CombOGF can create those generating functions.

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.

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## #115 2012-04-30 05:40:32

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Generating Functions

You missed alot of what I am trying to say by sticking to the procedural
approach. It is not uncommon for people being introduced into new
fields to try to keep what they already know.

While this is usually a good idea in the case of programming it can
be disastrous. I wanted you to tear down your Pascal or Basic famework
and learn another 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.

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## #116 2012-04-30 05:42:48

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Generating Functions

But this solution works.It is applicable in many situations.

Last edited by anonimnystefy (2012-04-30 05:42:59)

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.

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## #117 2012-04-30 05:47:32

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Generating Functions

I understand that it is tough to do what I ask. Of the two people I taught neither could accomplish it. Perhaps you remember this:

Yibka: Once you start down the path of procedural programming forever will it
dominate your destiny, consume you it will as it did Bit One's apprentice.

Lukky: Is the procedural paradigm stronger?

Yibka: No, no no! Easier! More seductive...

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.

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## #118 2012-04-30 05:49:15

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Generating Functions

I do not remember that.Where is that from?

But,I am willing to try if you have the patience.

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.

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## #119 2012-04-30 05:53:20

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Generating Functions

I do not remember that.Where is that from?

I think we have been lied to on every level by our masters. I was assured many times that that was standard knowledge.

But,I am willing to try if you have the patience.

I have the patience but do have I have the lifespan of several millenia?

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.

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## #120 2012-04-30 05:57:31

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Generating Functions

Well you have already live hundreds of millenia,so that won't be the problem.Let's get started if you want.

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.

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## #121 2012-04-30 05:58:50

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Generating Functions

Show me a full output of your best and most complicated example using your function.

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.

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## #122 2012-04-30 06:25:40

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Generating Functions

Hi bobbym

Inout:

``````list : [1,2,3,4,5,6,7,8,9,10,11,12,13];
CombOGF(list);``````

Output;

``````[1,2,3,4,5,6,7,8,9,10,11,12,13]
(%o74) (x+1)*(x^2+x+1)*(x^3+x^2+x+1)*(x^4+x^3+x^2+x+1)*(x^5+x^4+x^3+x^2+x+1)*(x^6+x^5+x^4+x^3+x^2+x+1)*
(x^7+x^6+x^5+x^4+x^3+x^2+x+1)*(x^8+x^7+x^6+x^5+x^4+x^3+x^2+x+1)*(x^9+x^8+x^7+x^6+x^5+x^4+x^3+x^2+x+1)*
(x^10+x^9+x^8+x^7+x^6+x^5+x^4+x^3+x^2+x+1)*(x^11+x^10+x^9+x^8+x^7+x^6+x^5+x^4+x^3+x^2+x+1)*
(x^12+x^11+x^10+x^9+x^8+x^7+x^6+x^5+x^4+x^3+x^2+x+1)*
(x^13+x^12+x^11+x^10+x^9+x^8+x^7+x^6+x^5+x^4+x^3+x^2+x+1)``````

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.

Offline

## #123 2012-04-30 06:38:33

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Generating Functions

Okay, how do you throw a die 4 times and get the probability of having the
sum of them equal 20?

Taking a break, be back in a while.

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.

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## #124 2012-04-30 06:50:17

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Generating Functions

Hi bobbym

35/1296?

Okay,see you later!

Last edited by anonimnystefy (2012-04-30 06:51:12)

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.

Offline

## #125 2012-04-30 07:55:41

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Generating Functions

That is correct! Okay, then use yours.

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.

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