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# numpy.polynomial.chebyshev.chebadd

`numpy.polynomial.chebyshev.``chebadd`(c1, c2)

  Add one Chebyshev series to another.

  Returns the sum of two Chebyshev series c1 + c2. The arguments are sequences of coefficients ordered from lowest order term to highest, 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 Array representing the Chebyshev series of their sum.

  See also

  `chebsub`, `chebmul`, `chebdiv`, `chebpow`

  Notes

  Unlike multiplication, division, etc., the sum of two Chebyshev series is a Chebyshev series (without having to “reproject” the result onto the basis set) so addition, 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.chebadd(c1,c2)
      array([ 4.,  4.,  4.])