ighest, i.e.,
[1,2,3] represents the series ``T_0 + 2*T_1 + 3*T_2``.

Parameters
----------
c1, c2 : array_like
    1-D arrays of Chebyshev series coefficients ordered from low to
    high.

Returns
-------
out : ndarray
    Of Chebyshev series coefficients representing their difference.

See Also
--------
chebadd, chebmulx, chebmul, chebdiv, chebpow

Notes
-----
Unlike multiplication, division, etc., the difference of two Chebyshev
series is a Chebyshev series (without having to "reproject" the result
onto the basis set) so subtraction, just like that of "standard"
polynomials, is simply "component-wise."

Examples
--------
>>> from numpy.polynomial import chebyshev as C
>>> c1 = (1,2,3)
>>> c2 = (3,2,1)
>>> C.chebsub(c1,c2)
array([-2.,  0.,  2.])
>>> C.chebsub(c2,c1) # -C.chebsub(c1,c2)
array([ 2.,  0., -2.])

)