class encapsulates monomials and polynomials

Hello ,
can you explain me what does this function ( class ) do ?

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1. class Doublet:
2.     def __init__(self,referenceMonome,refSuiv):
3.         self.refMon = referenceMonome
4.         self.suiv = refSuiv
5.     def __repr__(self):
6.         res=''
7.         cour=self
8.         while cour!=None:
9.             res+=str(cour.refMon)
10.             cour=cour.suiv
11.         if res[0]=='+':
12.             return res[1:]
13.         return res   

thank you

I don't know French and don't know many who do, and much of this lacks any context, but:
If suiv is "next" then this it looks like this is a linked list of some type and when this object's repr() is called, it returns referenceMonome from each member in the chain. It then removes the "+" from the head of the result.
It would be very helpful if you could translate your posts for us (non-bilingual) experts. Thanks,
Barton

Hello ,
can you explain me what does this function ( class ) do ?

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1. class Doublet:
2.     def __init__(self,referenceMonome,refSuiv):
3.         self.refMon = referenceMonome
4.         self.suiv = refSuiv
5.     def __repr__(self):
6.         res=''
7.         cour=self
8.         while cour!=None:
9.             res+=str(cour.refMon)
10.             cour=cour.suiv
11.         if res[0]=='+':
12.             return res[1:]
13.         return res   

thank you

Monome - Monomial? Like Barton, I don't know French.
It looks like the class is accumulating a series of monomials - similar to another of your threads. A monomial is an algebraic expression containing only one term as in: Just guessing.

Monome - Monomial? Like Barton, I don't know French.
It looks like the class is accumulating a series of monomials - similar to another of your threads. A monomial is an algebraic expression containing only one term as in:

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1. 7*x**2

Just guessing.

I thought maybe it's collecting friends. Could be.

Hello
i'm sorry , I had not given many details which could have
helped you to better include/understand my question
here is my problem
the framed functions are given
# Polynomials with two variables:
# the choices:
# the monomials which make a polynomial make only this polynomial:
# they do not compose of another polynomial
# if two polynomials contain the same monomial, this monomial exists in two specimens
# the monomials of a polynomial NEVER have null coefficient


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the functions which follow, I must correct them and/or supplement them

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for example , the calss Doublet causes problems to me
this returns an error message

could you help me PLEASE?
thank you in advance and I hope to have been clear ( understood )
thank you

I've added [ code] [ /code] tags. I'll take a look now. In the mean time, please learn to use these (without spaces) in "Posting Guidelines" in several places on this forum.

Hello bartonc ,
can you change the title please ?
thanks

thank you bartonc :)

I added spaces at the plus and minus signs so the polynomial is easier to read.
Output:
The first argument to Doublet is a Monome object and the second is None or a Doublet object

badech,

I was playing with an instance of your Doublet class and noticed there was no iteration method. I have never used 'yield' in code before:
Example:
It seems interestingly simple. Maybe you can use it.

badech,

I was playing with an instance of your Doublet class and noticed there was no iteration method. I have never used 'yield' in code before:

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1. # Doublet iterator
2. def iterDoub(d):
3.     while d:
4.         yield d.refMon
5.         d = d.suiv

Example:

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1. >>> print "Doublet 'd1':", d1
2. Doublet 'd1':  + 9*x^2*y^6 + 2*x^3*y^0 + 5*x^3*y^9 - 2*x^4*y^2 + 5*x^10*y^3 - 3*x^11*y^7
3. >>> for d in iterDoub(d1):
4. ...     print d
5. ...     
6.  + 9*x^2*y^6
7.  + 2*x^3*y^0
8.  + 5*x^3*y^9
9.  - 2*x^4*y^2
10.  + 5*x^10*y^3
11.  - 3*x^11*y^7
12. >>> 

It seems interestingly simple. Maybe you can use it.

Great post, B.V.! It's awesome that you are finding inspiration from members' questions.

Great post, B.V.! It's awesome that you are finding inspiration from members' questions.

Thanks Barton. I am learning new things regularly by following threads and participating where I can.

badech - Have you made any progress on your assignment? Show us what you have accomplished. Try to solve it one step at a time. We should not write it for you, but I am sure we can help if you are having problems with your code.

I did not care for the way the multinomials were represented, so I reworked special methods '__repr__': This is what it looks like now:

Thanks Barton. I am learning new things regularly by following threads and participating where I can.

badech - Have you made any progress on your assignment? Show us what you have accomplished. Try to solve it one step at a time. We should not write it for you, but I am sure we can help if you are having problems with your code.

I often wish that I had more time to play with some of these exercises. I'm right in the middle of good sized project with a deadline looming.

Maybe no progress, maybe just (less that avid poster) - I know that he checked in this morning.

Hello
I am blocked on the first question, I do not manage to write the function insereMonome because I do not understand how the "calss" function.
can you help me to write this first function , and then i'll do the others
thank you

Hello
I am blocked on the first question, I do not manage to write the function insereMonome because I do not understand how the "calss" function.
can you help me to write this first function , and then i'll do the others
thank you

Perhaps this is what you are looking for?

Hello
I am blocked on the first question, I do not manage to write the function insereMonome because I do not understand how the "calss" function.
can you help me to write this first function , and then i'll do the others
thank you

The sort function acts like a bubble sort. I learned this from a thread a couple of weeks ago. Function 'insereMonome' is a wrapper for the 'Doublet' class and returns a sorted Doublet object. Sample output:
Here's a hint to simplify a multinomial Doublet object:
Iterate on the object and create a dictionary where you can sum coefficients with like exponents. From the dictionary, create and return a new and simplified Doublet object, skipping a monomial with a coeffieient of 0.

euh...
no
these functions are given
i want to write a function which allows to insert a monomial in a polynomial
for example , if
P=2*X^5*Y^3+5*X^3*Y^7-2
and M= -7*X^4Y^6
then
insereMonome(M,P) returns
2*X^5*Y^3 -7*X^4Y^6 +5*X^3*Y^7-2

perfect ...
thank you very much bvdet :)

I often wish that I had more time to play with some of these exercises. I'm right in the middle of good sized project with a deadline looming.

Maybe no progress, maybe just (less that avid poster) - I know that he checked in this morning.

I understand about deadlines. I will have some coming up in the near future. Now you know where I will be if I disappear for a few days.

what do you think about this one ?

def ajouteDoubletsRec(listeDoublet1, listeDoublet2): #ajoute=add
...
# ATTENTION: not to forget to treat the case where two opposite
# monomials are added!!!!!
# in this case, not to reveal a monomial with a null coefficient.
return None

...this part is missing

what do you think about this one ?

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1. def ajouteDoubletsRec(listeDoublet1, listeDoublet2):
2.     # renvoie une nouvelle liste de doublets obtenue par
3.     # fusion des deux listes en une nouvelle
4.     # ATTENTION : ne pas oublier de traîter le cas où l'on additionne deux monomes opposés !!!!!
5.     # dans ce cas, NE PAS faire apparaître un monome avec un coefficient nul.
6.     if listeDoublet1==None :
7.         return listeDoublet2
8.     elif listeDoublet2==None :
9.         return listeDoublet1
10.     else :
11.         listeDoublet1.suiv=ajouteDoubletsRec(listeDoublet1.suiv, listeDoublet2)
12.     sortDoub(listeDoublet1)
13.     return listeDoublet1

badech,

The function creates a never ending loop. You need to test your code in an IDE such as Pythonwin or Idle.

Remember that a Doublet is a combination of a Monome and another Doublet. I suggest that you iterate on one of the Doublets and combine each iteration Monome with the other Doublet.
You will need to write the simplification function. See my earlier post for suggestions. Test your code, and it should look something like this (Pythonwin):

I have another improvement (in my mind) for the displayed representation of a Monome object: Since a number raised to the '0' power == 1, it need not be included in the representation:

Here is another function for sorting a Doublet object. The sort itself should be much faster because it uses the built-in list.sort() method, but the sort list is created by iteration. List items can be deleted or moved around to change the sort results. It returns a sorted Doublet object, so the object can be passed directly to a return statement or assigned to a variable.
Sample output: HTH