I'm not used to reply-all
---------- Forwarded message ---------- From: <josef.p...@gmail.com> Date: Tue, Jan 10, 2012 at 10:20 AM Subject: Re: [Matplotlib-users] How to plot Chebyshev polynolmials To: Fabien Lafont <lafont.fab...@gmail.com> On Tue, Jan 10, 2012 at 9:46 AM, Fabien Lafont <lafont.fab...@gmail.com> wrote: > No I just want to plot the third Shebitchev polynomial. the vander functions give you the basis functions for a given x, or use coefficients only for the polynomial you want, if I understand correctly what you want >>> import numpy as np >>> from numpy import polynomial as poly >>> chebs = [poly.Chebyshev(coef) for coef in np.eye(5)] >>> for p in chebs: plt.plot(x, p(x)) ... [<matplotlib.lines.Line2D object at 0x046D91F0>] [<matplotlib.lines.Line2D object at 0x046D9510>] [<matplotlib.lines.Line2D object at 0x046D9830>] [<matplotlib.lines.Line2D object at 0x046D9B50>] [<matplotlib.lines.Line2D object at 0x046D9E70>] >>> plt.show() or >>> plt.plot(poly.chebvander(x, 5)) Josef > > 2012/1/10 Daniel Hyams <dhy...@gmail.com>: >> I think that you're misusing Chebyshev (do you really only want to give "3" >> as a coefficient..which is just the constant function 3), and you have to >> evaluate it in order to give matplotlib some x and y data to plot. >> >> from matplotlib import pyplot as plt >> import numpy as np >> >> x = np.linspace(-1.0,1.0) >> test = np.polynomial.Chebyshev((1,2,3)) >> y = test(x) >> plt.plot(x,y) >> plt.show() >> >> >> >> On Tue, Jan 10, 2012 at 9:10 AM, Fabien Lafont <lafont.fab...@gmail.com> >> wrote: >>> >>> 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 >>> >>> >>> ------------------------------------------------------------------------------ >>> Write once. Port to many. >>> Get the SDK and tools to simplify cross-platform app development. Create >>> new or port existing apps to sell to consumers worldwide. Explore the >>> Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join >>> http://p.sf.net/sfu/intel-appdev >>> _______________________________________________ >>> Matplotlib-users mailing list >>> Matplotlib-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users >> >> >> >> >> -- >> Daniel Hyams >> dhy...@gmail.com >> >> ------------------------------------------------------------------------------ >> Write once. Port to many. >> Get the SDK and tools to simplify cross-platform app development. Create >> new or port existing apps to sell to consumers worldwide. Explore the >> Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join >> http://p.sf.net/sfu/intel-appdev >> _______________________________________________ >> Matplotlib-users mailing list >> Matplotlib-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/matplotlib-users >> > > ------------------------------------------------------------------------------ > Write once. Port to many. > Get the SDK and tools to simplify cross-platform app development. Create > new or port existing apps to sell to consumers worldwide. Explore the > Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join > http://p.sf.net/sfu/intel-appdev > _______________________________________________ > Matplotlib-users mailing list > Matplotlib-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-users ------------------------------------------------------------------------------ Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users