def poly(x_list, seed):
    """Return cordinates of a polynomial.

    This function returns the 2-D cordinates of a polynomial, and is used
    for interpolation problems.

    Parameters
    ----------
    x_list : list
        A list of numerics that defines the x values evaluated over.

    seed : array-like, shape = (parameters, 2)
        A numpy array of parameters generated by paddy.  Refer to
        :mod:`~paddy.Paddy_runner` for details regarding generation of the
        array.

    Returns
    -------
    output : list of floats
        A list of float values representing the y values of the input x.

    See Also
    --------
    :func:`eval_numeric`

    Notes
    -----
    The polynomial is defined as:

    .. math:: \\sum_{k=0}^{n}a_{k}x^k

    Where ``a`` represents the sequence of parameter values generated by
    paddy.  ``x`` is simply the `x` parameter of numeric values that the
    polynomial is evaluated over.

    """
    counter = 0
    output = []
    s_x = []
    while counter < len(x_list):
        k = 0
        xn_out = []
        while k < len(seed):
            temp_y = seed[k][0] * x_list[counter] ** k
            xn_out.append(temp_y)
            k = k + 1
        s_x.append(sum(xn_out))
        counter = counter + 1
    output = s_x
    return output
