Alex Renelt wrote:
Alex Renelt wrote:
in addition:
I'm writing a class for polynomial manipulation. The generalization of the above code is:
definitions: 1.) p = array([a_0, a_i, ..., a_n]) represents your polynomial P(x) = \sum _{i=0} ^n a_i x^i
2.) deg(p) is its degree
3.) monic(p) makes P monic, i.e. monic(p) = p / p[:-1]
then you get: from numarray import * import numarray.linear_algebra as la
def roots(p): p = monic(p); n = deg(p) M = asarray(zeros((n,n)), typecode = 'f8') # or 'c16' if you need complex coefficients M[:-1,1:] = identity(n-1) M[-1,:] = -p[:-1] return la.eigenvalues(M)
Alex
uhh, I made a mistake: under definitions, 3.) its "monic(p) = p / p[-1]" of course
Alex
Alex,
If you want a class for polynomial manipulation, you should check out my ratfun module.
http://calcrpnpy.sourceforge.net/ratfun.html
Ray
Ray,
thanks a lot for your hint but I'm writing it for a students paper in a german math class so I believe I should better do some work alone ;-)
In addition I only need a class for polynomials and not for rational functions and I'm testing different iterative polynomial solvers. So I'm happy to have my own small class which I understand 100%.
Generally I'm against rediscovering the wheel again and again!
Alex -- http://mail.python.org/mailman/listinfo/python-list
