Hi everybody, I noticed a strange behavior of the sph_jn function (and it really bothers me!). Here is a copy-past of what I get (from scipy.special import sph_jn) in IPython: In [1]: sph_jn(2,3350.506) Out[1]: (array([ 2.98461400e-04, -6.76491641e-07, -2.98462005e-04]), array([ 6.76491641e-07, 2.98461803e-04, -4.09252598e-07])) In [2]: sph_jn(2,3350.507) Out[2]: (array([ inf, -3.78029638e-07, -inf]), array([ 3.78029638e-07, inf, inf])) As you can see, there is a 'jump' (a very big one!) between 3350.506 and 3350.507 for some orders and some derivatives. What happens ? As a point of comparison, Mathematica (http://www.wolframalpha.com/input/?i=SpericalBesselJ[2%2C3350.507]) says: J_2(3350.507) ~= -0.000298462... wich seems to be far more correct. Is there any 'numerical disaster' ? Thanks, Yann