[Date Index] [Thread Index] [Author Index]

Re: NDSolve Question

• To: mathgroup at smc.vnet.net
• Subject: [mg86331] Re: NDSolve Question
• From: "David Park" <djmpark at comcast.net>
• Date: Sat, 8 Mar 2008 05:44:47 -0500 (EST)

I found the answer, which is to use:

f[q_?NumberQ]:= ...

which prevents an initial evaluation.

-- 
David Park
djmpark at comcast.net
http://home.comcast.net/~djmpark/


"David Park" <djmpark at comcast.net> wrote in message news:...
> Suppose I have a system like the following:
>
> f[q_]= some function with side affects
>
> NDSolve[{x'[t]==f[x[t]], x[0]==0},{x},{t, 0, 1}]
>
> My problem is that f[x[t]] seems to be evaluated before NDSolve starts 
> solving the equations and hence the routines always use the initially 
> evaluated form. I would like to have f[x[t]] to not be initially 
> evaluated. Is that possible with NDSolve? Is there any particular Method 
> or Option that can control the initial evaluation?
>
> -- 
> David Park
> djmpark at comcast.net
> http://home.comcast.net/~djmpark/
>
>