Recent content by matoma28

Thanks a lot! It turns out that my function was not analytical at the point of interest, that is why Mathematica did not know which (directional) derivative to give me. Thanks for your response.

Can anyone help on this? I am calculating the magnetic susceptibility, essentially a second derivative evaluated at zero magnetic field. The problem is that sometimes Mathematica works perfectly, and sometimes it gives me a "1/0 complexinfinity" error message, with no obvious reason. The...