Dear all, I'm frustrated by some ODE problems. sorry the form is a little bit complex: solution := dsolve([diff(s(t),t) = A - A * rho^((1 - r^(theta * t)) * x) - v, diff(f(t),t)=((c - s(t)) / l) * m + x, diff(h(t),t) = x, f(0) = 0, s(0) = 0, h(0) = 0], numeric); for this problem no closed-form, only numerical solution can be found. I have following questions: (1) why cannot I evaluate the value of f(t) at t=5 by using f(5)? (2) For each fixed x, there are curves s(t), f(t), and h(t). Given s(tau) = c, I want to find f(tau)=?. How can I do that? Do I need to find tau first, then find f(tau)? How?

You may have noticed that we've introduced prizes to get people more involved ... bribery is not beyond this crew to make this site successful.

Chi^2 calculations above some "size" or "complexity", using Maple 9.5 and Global Optimization Toolbox (GOT), may produce after some time of calculation error messages like:

"Execution stopped: stack limit reached.
The kernel has been shut down. Further computation cannot be performed."

Seeking workarounds, I have looked for information at ?kernelopts for kernelopts(stacklimit), but it was not very useful:

"Limits may be raised or lowered. Maple limits may not be raised above any system defined hard limits. "

A question was asked in the forums about series tests. I saw that this would also make an excellent weblog entry as well. In answer to the questions: How can I get Maple to determine if a series converges or diverges? and How can I obtain the general representation of a formal power series for a function? I offer the following advice:

Welcome! This forum is for talking about anything that has to do with Maple and mathematics. The moderator for this forum is Stephen Forrest.