How to take the time t of ode to a new variable?

Hi,everyone,I have a question to require you, the differential equation is D(X'')+C(X')+G=u,where u is a known nonlinear curve,D,C,G are constant parameters.I use ode to solve the equation,when I use time t to fit u of the equation,I can nearly get the rough answer of X with t. my question is:if I do not fit u of the equation, and set the time interval to get the curve's pot,and solve the equation step by step, for example,I get u curve's pot of the time [0,0.0002,0.0004,0.0006...], and solve the equation step by step,how can i realize the final answer?Look forward to your reply! Thanks very very much!

                                        yours ding

Answer 1

[Miro]

hi, so as far as i understood you want to minimize the function. So what wou need to do is using the matlab fundtion fminsearch for the function D(X'')+C(X')+G-u=0