hello markus,
yes, i am trying to solve the scattering of cylindrical nanoparticles, or better said in my special case µm particles. i have tried your advise with arbitrary precision number, but still the error arise.
dn[mmm_, j_] := ((BesselJ[mmm - 1, j]/BesselJ[mmm, j]) - mmm /
j) (*logaritmic deriviate *)
from my nb is the troublemaker.
After changing in
dn[mmm_, j_] :=
Block[{$MaxExtraPrecision = 1000},
N[((BesselJ[mmm - 1, j]/BesselJ[mmm, j]) - mmm /j),
700]] (*logaritmic deriviate *)
the same error showed up.
Fortunatly i solved my problem 2 days ago with a bypass.
thx for your help.
best regards
walter