[Matplotlib-users] How to plot Chebyshev polynolmials

[Fabien L. <laf...@gm...>]

I'm trying to plot Chebyshev polynolmials using: numpy.polynomial.Chebyshev:


import math
from numpy import *
from numpy import polynomial as pol
from pylab import *
from scipy import *
from scipy import optimize
import warnings
warnings.simplefilter('ignore', np.RankWarning)


test = pol.Chebyshev(3)
print test
plot (test)


show()
=======================================================================

The print return:      cheb([ 3.])

=======================================================================
and plot :


Traceback (most recent call last):
  File "T:\Dropbox\Thèse\Python\fit sonde\test_poly_Tcheb.py", line
32, in <module>
    plot (test)
  File "C:\Python27\lib\site-packages\matplotlib\pyplot.py", line 2458, in plot
    ret = ax.plot(*args, **kwargs)
  File "C:\Python27\lib\site-packages\matplotlib\axes.py", line 3849, in plot
    self.add_line(line)
  File "C:\Python27\lib\site-packages\matplotlib\axes.py", line 1443,
in add_line
    self._update_line_limits(line)
  File "C:\Python27\lib\site-packages\matplotlib\axes.py", line 1451,
in _update_line_limits
    p = line.get_path()
  File "C:\Python27\lib\site-packages\matplotlib\lines.py", line 644,
in get_path
    self.recache()
  File "C:\Python27\lib\site-packages\matplotlib\lines.py", line 401, in recache
    y = np.asarray(yconv, np.float_)
  File "C:\Python27\lib\site-packages\numpy\core\numeric.py", line
235, in asarray
    return array(a, dtype, copy=False, order=order)
TypeError: float() argument must be a string or a number