def poly_approx( x, y, m ):
    """Compute an approximation polynomial of degree m for the points (x,y)"""

    s = np.zeros( x.shape )
    r2 = 0

    V = np.vander( x, increasing=True )

    feck = la.solve(V, y)

    s = feck[0:m+1]

    V_cut = V[:,:m+1]

    r2 = la.norm( np.matmul(V_cut, s) - y )
    return s, r2