U ?hw@sTz ddlZWnek r YnXzddlmZWnek rFYnXddZdS)Nxcst}tfddt|D}t|td|}|dg}t|D]}||d|qJt dg}td|D]"}||| t|d|q|dd|D}|S)aGiven a series f(x) = a[1]*x + a[2]*x**2 + ... + a[n-1]*x**(n - 1), use the Lagrange inversion formula to compute a series g(x) = b[1]*x + b[2]*x**2 + ... + b[n-1]*x**(n - 1) so that f(g(x)) = g(f(x)) = x mod x**n. We must have a[0] = 0, so necessarily b[0] = 0 too. The algorithm is naive and could be improved, but speed isn't an issue here and it's easy to read. c3s|]}|t|VqdS)Nr).0iaQ/var/www/html/venv/lib/python3.8/site-packages/scipy/special/_precompute/utils.py sz%lagrange_inversion..rcSsg|]}t|qSr)mpmpf)rrrrr %sz&lagrange_inversion..) lensumrangerZseriesZremoveOappendexpandr rZcoeff)rnfhZhpowerkbrrr lagrange_inversion s    r)Zmpmathr ImportErrorZ sympy.abcrrrrrr s