Polynomial conversion should not change the function

[jishnub]

Currently conversion between polynomial types passes the coefficients on directly to the constructor. As an example,

julia> x² = Polynomial([0,0,1])
Polynomial(x^2)

julia> ChebyshevT(x²)
ChebyshevT(1⋅T_2(x))

It would have been better here if the constructor returned the Chebyshev polynomial decomposition of x², rather than using the coefficients directly. The present behavior changes the function, which arguably shouldn't happen.

[jverzani]

Yes, definitely a bug. They should represent the same polynomial in different bases up to floating point. Thanks for the heads up

[jverzani]

Many thanks. Fixed and tagged.