# numpy.polynomial.chebyshev.poly2cheb¶

`numpy.polynomial.chebyshev.``poly2cheb`(pol)[source]

Convert a polynomial to a Chebyshev series.

Convert an array representing the coefficients of a polynomial (relative to the “standard” basis) ordered from lowest degree to highest, to an array of the coefficients of the equivalent Chebyshev series, ordered from lowest to highest degree.

Parameters: pol : array_like 1-D array containing the polynomial coefficients c : ndarray 1-D array containing the coefficients of the equivalent Chebyshev series.

Notes

The easy way to do conversions between polynomial basis sets is to use the convert method of a class instance.

Examples

```>>> from numpy import polynomial as P
>>> p = P.Polynomial(range(4))
>>> p
Polynomial([0., 1., 2., 3.], domain=[-1,  1], window=[-1,  1])
>>> c = p.convert(kind=P.Chebyshev)
>>> c
Chebyshev([1.  , 3.25, 1.  , 0.75], domain=[-1.,  1.], window=[-1.,  1.])
>>> P.chebyshev.poly2cheb(range(4))
array([1.  , 3.25, 1.  , 0.75])
```

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