For solving nonlinear equations I use AdamsBDF solver. However, varying the number of discretization intervals (controlled by the variable "intvls") results in solutions quite different from one another. How can one determine the optimum number of intvls. I tried it by plotting the solutions by increasing the number of intervals till the two successive solution produce the same result. Is there any other way to find the optimum number of intervals?
Question 2 -
In oscillation problems, I am interested in knowing only the time required for a pendulum to reaach equilibrium (theta =0).
I do not want to get the entire solution but am interested only up to when the soultion reaches zero the first time. This is when the initial value of angle theta from vertical axis is given and I wish to find when it reaches zero the first time. How do I do this?