Compute the roots of a Chebyshev series.
Return the roots (a.k.a “zeros”) of the C-series represented by cs, which is the sequence of the C-series’ coefficients from lowest order “term” to highest, e.g., [1,2,3] represents the C-series T_0 + 2*T_1 + 3*T_2.
Parameters : | cs : array_like
|
---|---|
Returns : | out : ndarray
|
See also
polyroots
Notes
Algorithm(s) used:
Remember: because the C-series basis set is different from the “standard” basis set, the results of this function may not be what one is expecting.
Examples
>>> import numpy.polynomial.chebyshev as cheb
>>> cheb.chebroots((-1, 1,-1, 1)) # T3 - T2 + T1 - T0 has real roots
array([ -5.00000000e-01, 2.60860684e-17, 1.00000000e+00])