> One thing, is there any way of passing a list/tuple to the function, e.g. > > vars = (x,y) > Poly(x+2*y, vars)
You must unpack a tuple or a list when passing to a constructor: In [26]: Poly(x+2*y, x, y) Out[26]: Poly((1, 2), ((1, 0), (0, 1)), (x, y), 'grlex') In [27]: symbols = (x, y) In [28]: Poly(x+2*y, *symbols) Out[28]: Poly((1, 2), ((1, 0), (0, 1)), (x, y), 'grlex') In [29]: symbols = [x, y] In [30]: Poly(x+2*y, *symbols) Out[30]: Poly((1, 2), ((1, 0), (0, 1)), (x, y), 'grlex') See info in Python Tutorial: http://docs.python.org/tut/node6.html#SECTION006740000000000000000 Mateusz 2008/3/29, Colin Gillespie <[EMAIL PROTECTED]>: > > 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 no longer maintained.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 > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sympy?hl=en -~----------~----~----~----~------~----~------~--~---
