(* Code for calculating the Fredholm determinant for the pinball problem *) Get["orbits.m"] t[n_] := Exp[s Tp[n]] z^np[n]/Abs[lam[n]] B[p_,r_] := -t[p]^r/(r (1-lam[p]^(-r))^2) logFred = Series[Sum[Sum[B[p,r] , {r,1,Floor[7/np[p]]}], {p,0,40}], {z,0,7}] Fred = Exp[logFred] gamma[m_] := Block[{fred1}, fred1 = Normal[Series[Fred, {z,0,m}]] /.z->1; N[s /. FindRoot[fred1==0, {s, 0.4}], 16] ] gam = Table[gamma[i], {i,1,6}] Print["Escape rate = ", gam]Save["tmp.dat", Fgam] fred1 = Fred /. s -> gamma[6] Plot[Evaluate[Normal[fred1]], {z, -100, 100}] ListPlot[Log[Abs[fred1[[3]]]]]