Problems(discontinuous condition) in Rkfixed

[ptc-3308012]

I want to put an Odesolver into a program, so I use rkfixed, but it is not working if I add the 'if statement'

\Anyone one know how to solve this?

Thanks!

Rong

[ValeryOchkov]

RONG XU wrote:

I want to put an Odesolver into a program, so I use rkfixed, but it is not working if I add the 'if statement'

\Anyone one know how to solve this?

Thanks!

Rong

1) Send please the Mathcad file too.

2) We can use the odesolve function in a program to by a creating a user function f(...):= odesolve(...) and by colling this function f(...) in the program.

[ptc-3308012]

Thanks for reply!

Attached is the mathcad file. If you cannot open it, plz let me know.

And do you have example of function():=odesovler()

Best regard

Rong

[ViktorKorobov · Accepted solution]

Viktor

[ptc-3308012]

Thanks. It worked out good. Can you explain why use Y[0](first vector value) instead of Y?

[ViktorKorobov]

RONG XU wrote:

Thanks. It worked out good. Can you explain why use Y[0](first vector value) instead of Y?

The best explanation can be found in Help:

QuickSheets/ CALCULUS AND DIFFERENTIAL EQUATIONS /Solving a First-Order ODE Initial Value Problem

Viktor

[ValeryOchkov]

RONG XU wrote:

And do you have example of function():=odesovler()

Best regard

Rong

http://communities.ptc.com/message/188186#188186

[ptc-3308012]

thanks!