fitting data with numpy

Question

Let me start by telling that what I get may not be what I expect and perhaps you can help me here. I have the following data:

>>> x
array([ 3.08,  3         


        

Answer 1

Note that you can use the Polynomial class directly to do the fitting and return a Polynomial instance.

from numpy.polynomial import Polynomial

p = Polynomial.fit(x, y, 4)
plt.plot(*p.linspace())

p uses scaled and shifted x values for numerical stability. If you need the usual form of the coefficients, you will need to follow with

pnormal = p.convert(domain=(-1, 1))