OK I've found Poly - it's exactly what I want. One thing, is there any
way of passing a list/tuple to the function, e.g.
vars = (x,y)
Poly(x+2*y, vars)
Cheers
Colin
On Mar 29, 4:33 pm, "Mateusz Paprocki" <[EMAIL PROTECTED]> wrote:
> > I don't have a function Poly . I presume I should use Polynomial
>
> Poly, and 'polys' module was added after 0.5.13 release, so if
> you wish to use this you would need latest HG repository.
>
> Of course you can use Polynomial, however the interface
> is a bit different. Note also that 'polynomials' module is
> no longer maintained.
>
> In [19]: f=2*x**3+3*x*y+1
>
> In [20]: p = Polynomial(f, var=x)
>
> In [21]: p.degree()
> Out[21]: 3
>
> In [22]: q = Polynomial(f, var=(x,y))
>
> In [23]: q.degree()
> Out[23]: 3
>
> Mateusz
>
> 2008/3/29, Colin Gillespie <[EMAIL PROTECTED]>:
>
>
>
> > Thanks for the quick response.
>
> > When I do
> > from sympy import *
> > I don't have a function Poly . I presume I should use Polynomial
> > instead?
>
> > Cheers
>
> > Colin
>
> > On Mar 29, 3:54 pm, "Mateusz Paprocki" <[EMAIL PROTECTED]> wrote:
> > > Hi,
>
> > > given the following input
>
> > > In [1]: f=2*x**3+3*x*y+1
>
> > > we get an expression:
>
> > > In [2]: type(f)
> > > Out[2]: <class 'sympy.core.add.Add'>
>
> > > You can convert this to a polynomial:
>
> > > In [3]: p = Poly(f, x)
>
> > > In [4]: p
> > > Out[4]: Poly((2, 3*y, 1), ((3,), (1,), (0,)), (x,), 'grlex')
>
> > > and then:
>
> > > In [5]: p.degree
> > > Out[5]: 3
>
> > > In [6]: p.coeff(0)
> > > Out[6]: 1
>
> > > In [7]: p.coeff(1)
> > > Out[7]: 3*y
>
> > > In [8]: p.coeff(2)
> > > Out[8]: 0
>
> > > In [9]: p.coeff(3)
> > > Out[9]: 2
>
> > > The same way you can work with MV polynomials:
>
> > > In [10]: q = Poly(f, x, y)
>
> > > In [11]: q
> > > Out[11]: Poly((2, 3, 1), ((3, 0), (1, 1), (0, 0)), (x, y), 'grlex')
>
> > > In [12]: q.degree
> > > Out[12]: 3
>
> > > In [13]: q.coeff(3, 0)
> > > Out[13]: 2
>
> > > In [14]: q.coeff(2, 1)
> > > Out[14]: 0
>
> > > For more information refer to 'polys' module docstrings, eg. Poly? in
> > ipython.
>
> > > Mateusz
>
> > > 2008/3/29, Colin Gillespie <[EMAIL PROTECTED]>:
>
> > > > Dear All,
>
> > > > Are there any inbuilt function to work with degrees of polynomials?
> > > > For example,
>
> > > > x=Symbol('x')
> > > > y=symbol('y')
>
> > > > f=2*x**3+3*x*y+1
>
> > > > So
>
> > > > f.highestDegree(x) would return 3
> > > > f.coeff(x**1) would return 3*y
>
> > > > Many thanks
>
> > > > Colin
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