"When using ode, I used the following format."
Do not use that deprecated syntax. The best way to pass extra parameters is to use an anonymous function, exactly as the ODE45 documentation recommends:
"Is the order in [] set?"
Yes, and what its output arguments are is explained in the ODE45 documentation.
"If you enter [t C q], t and C seem to be called by ode. I wonder what q stands for at this time!!"
Rather than wondering, guessing, and then asking random strangers on the internet it is much simpler to read the ODE45 documentation, which explains what every output argument is:
The ODE45 documentation has a section entitled "Output Arguments", which explains the outputs.
