Home › Forums › Get Help › How do I ...? with Maple

Sounds simple, but I get errors for trying to control DSOLVE,NUMERIC stepsize?!?!?!?!

Posted on 2008-05-04 22:06 By sbh (Maple Rating 1 11)
Categories:

 

View 1620_FD1at1SDZat1andNWIP.mw on MapleNet or Download 1620_FD1at1SDZat1andNWIP.mw
View file details

Hello All,

I am solving a parabolic PDE using the method of lines (not using pdetools) and so I have a procedure that writes out the N ODEs.  The only problem I currently have is trying to monitor the CFL condtion.  In essence I need to know how (if possible) I can control the stepsize explicitly for the dsolve,numeric command.  This sounds simple and I feel I must be overlooking something.  

In the worksheet is more, and better, documentation about what is going on.

 

Thanks sincerely,

Steve

 

‹ Programming with Maple 7 multiple integal ›
Robert Israel's picture

stepsize

Comment on 2008-05-05 01:34 from Robert Israel (Maple Rating 4 1460)

Most of the dsolve,numeric methods, including the default rkf45, are adaptive, so there is no such thing as a fixed step size.  The help page suggests using the range option in dsolve (which you already have) together with the refine option of odeplot.  If you need a fixed step size, you could try one of the classical methods: see ?dsolve,classical.

Thanks Robert, That was

Comment on 2008-05-05 14:58 from sbh (Maple Rating 1 11)

Thanks Robert,

That was indeed a good way to go.  Thanks a lot for your quick reply,

Steve

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
}