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help with equation

 Hi, everyone!Thank you for your attention.I got to solve numerically higly non-linear equation and get the following error.I use Octave 3.6.3 and lsode seemingly is the only included ode.Best wishes, lan function xdot = f (x, t);ep=0.000001;si=-1;a=2;C=100;xdot = [x(2), -ep/si*(-a*x(1)^(a-1)+C+2*si/t*tanh(x(2)/ep))*cosh(x(2)/ep)^2]';endfunctionx0 = [100; 1]';t = linspace(1, 12, 10000)';lsode_options ("integration method", "stiff")x = lsode ("f", x0, t);plot(x(:,1), t);print -deps R.epLSODE-- WARNING..INTERNAL T (=R1) AND H (=R2) ARE SUCH THAT IN THE MACHINE, T + H = T ON THE NEXT STEP (H = STEP SIZE). SOLVER WILL CONTINUE ANYWAY In above, R1 = 0.1000000000000D+01 R2 = 0.0000000000000D+00 LSODE-- AT T (=R1) AND STEP SIZE H (=R2), THE CORRECTOR CONVERGENCE FAILED REPEATEDLY OR WITH ABS(H) = HMIN In above, R1 = 0.1000000000000D+01 R2 = 0.0000000000000D+00error: lsode: repeated convergence failures (t = 1; perhaps bad Jacobian supplied or wrong choice of integration method or tolerances)error: called from: _______________________________________________ Help-octave mailing list [hidden email] https://mailman.cae.wisc.edu/listinfo/help-octave