>> other solvers): at line 336, it should be >> >> vdelta = abs(y5 - y4);
> So number of evaluations and steps increased dramatically. I can see the same > for ode45..ode78. Can you send an example where I can see results becoming > better if I use your modification? vdelta is an error estimate (in fact, it is compared few lines below with the tolerance) if (all (vdelta <= vtau)) What happens if it is negative? Or, even worse, complex? Of course, without the absolute value you have less time steps, only because the comparison with the tolerance is a non-sense. Moreover, if you try to solve y'=sqrt(-1)*y you get the complex conjugate solution. In fact, the conjugate-transpose symbol ' is erroneously used instead of only-transpose .' I think I will have some time to further investigate the codes (at least, the m-files). Best regards, Marco ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ Octave-dev mailing list Octave-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/octave-dev