## matplotlib-users

 [Matplotlib-users] Fit with Chebyshev Polynomials From: Fabien Lafont - 2011-12-14 13:23:46 ```I have a basic problem (I think) I try to fit some data with this function http://docs.scipy.org/doc/numpy/reference/generated/numpy.polynomial.Chebyshev.fit.html But it return an error: fit = chebyshev.fit(T,R,3) NameError: name 'chebyshev' is not defined I don't understand I've imported Numpy and polynomials... An Idea? import math from numpy import * from numpy import polynomial from pylab import * from scipy import * from scipy import optimize import warnings warnings.simplefilter('ignore', np.RankWarning) R = [ 9011.5 , 7822.7 , 6253.9 , 4877.56 , 3892.08 , 3221.41 , 2647.05, 2260.94 , 1959.72 , 1712.06 , 1522.28 , 1367.87 , 1242.953 , 1185.092, 1104.452 , 1031.862 , 919.8644 , 832.9942 , 767.8944 , 715.1569, 671.6301 , 635.1634 , 604.284 , 577.5536] T = range(0,len(R)) plot (T,R,".") show() fit = chebyshev.fit(T,R,3) print fit ```
 Re: [Matplotlib-users] Fit with Chebyshev Polynomials From: Benjamin Root - 2011-12-14 13:33:44 Attachments: Message as HTML ```On Wednesday, December 14, 2011, Fabien Lafont wrote: > I have a basic problem (I think) > > I try to fit some data with this function > http://docs.scipy.org/doc/numpy/reference/generated/numpy.polynomial.Chebyshev.fit.html > > But it return an error: > > fit = chebyshev.fit(T,R,3) > NameError: name 'chebyshev' is not defined > > I don't understand I've imported Numpy and polynomials... An Idea? > > > import math > from numpy import * > from numpy import polynomial > from pylab import * > from scipy import * > from scipy import optimize > import warnings > warnings.simplefilter('ignore', np.RankWarning) > > > R = [ 9011.5 , 7822.7 , 6253.9 , 4877.56 , 3892.08 , > 3221.41 , 2647.05, > 2260.94 , 1959.72 , 1712.06 , 1522.28 , 1367.87 , 1242.953 > , 1185.092, > 1104.452 , 1031.862 , 919.8644 , 832.9942 , 767.8944 , 715.1569, > 671.6301 , 635.1634 , 604.284 , 577.5536] > > T = range(0,len(R)) > plot (T,R,".") > show() > fit = chebyshev.fit(T,R,3) > print fit > The function would be in the "polynomial" namespace. So "polynomial.chebyshev()" would work. To reduce typing, you can import a module "as" some other name. from numpy import polynomial as poly .. fit = poly.chebyshev.fit(T,R,3) Importing modules is very flexible and I suggest reading up on it. Ben Root ```
 Re: [Matplotlib-users] Fit with Chebyshev Polynomials From: Fabien Lafont - 2011-12-14 13:59:48 ```Thx Seb! 2011/12/14 Benjamin Root : > > > On Wednesday, December 14, 2011, Fabien Lafont > wrote: >> I have a basic problem (I think) >> >> I try to fit some data with this function >> >> http://docs.scipy.org/doc/numpy/reference/generated/numpy.polynomial.Chebyshev.fit.html >> >> But it return an error: >> >> fit = chebyshev.fit(T,R,3) >> NameError: name 'chebyshev' is not defined >> >> I don't understand I've imported Numpy and polynomials... An Idea? >> >> >> import math >> from numpy import * >> from numpy import polynomial >> from pylab import * >> from scipy import * >> from scipy import optimize >> import warnings >> warnings.simplefilter('ignore', np.RankWarning) >> >> >> R = [ 9011.5   ,  7822.7   ,  6253.9   ,  4877.56  ,  3892.08  , >> 3221.41  ,  2647.05, >>  2260.94 ,   1959.72  ,  1712.06   , 1522.28  ,  1367.87  ,  1242.953 >>  , 1185.092, >>  1104.452  , 1031.862  ,  919.8644  , 832.9942  , 767.8944  , 715.1569, >>   671.6301 ,  635.1634 ,  604.284   , 577.5536] >> >> T = range(0,len(R)) >> plot (T,R,".") >> show() >> fit = chebyshev.fit(T,R,3) >> print fit >> > > The function would be in the "polynomial" namespace.  So > "polynomial.chebyshev()" would work.  To reduce typing, you can import a > module "as" some other name. > > from numpy import polynomial as poly > > .. > > fit = poly.chebyshev.fit(T,R,3) > > Importing modules is very flexible and I suggest reading up on it. > > Ben Root ```