def _mergex(xlo, xhi):
    """
    We are assuming that points are consecutive, so that xlo[n]=xhi[n-1]
    This is usually valid for fits from a single spectrum, but breaks for
    simultaneous multiwavelength fitting
    """
    N = xlo.size
    x = np.zeros(N + 1)
    x[:N] = xlo.copy()
    x[-1] = xhi[-1]

    return x
def _mergex ( xlo , xhi ) : N = xlo . size x = np . zeros ( N + 1 ) x [ : N ] = xlo . copy ( ) x [ - 1 ] = xhi [ - 1 ] return x
We are assuming that points are consecutive, so that xlo[n]=xhi[n-1]
    This is usually valid for fits from a single spectrum, but breaks for
    simultaneous multiwavelength fitting