Question about NDSolve and loops
- Subject: [mg1268] Question about NDSolve and loops
- From: "Michael U. Bogatyriev" <mbog at tulgtu.tula.su>
- Date: Wed, 31 May 1995 02:25:38 -0400
- Apparently-to: mathgroup-send at christensen.cybernetics.net
- Organization: Tula Tech. University
Dear MathGroup,
I have a questions about NDSolve[.] function in Mma
and more generally - about outputs when doing loops.
1. It is declared that NDSolve [...., {t,t1,t2}] gives results
as InterpolatingFunction[.] which interpolates data on the [ t1
- t2] interval. Nevertheless I always get results interpolated
on the [0 - t2] intervals as in this simple example:
[In]:
dt=0.1;
t1=0.2;t2=0.3;
NDSolve[{y'[t]+y[t]==1,y[0]==0},y,
{t,t1,t2}]
Evaluate[y[t1+dt/2]/.%]
[Out}:
{{y -> InterpolatingFunction[{0., 0.3}, <>]}}
{0.221198}
I am modelling control systems which is changing differential
equations parameters on each step of modelling.
So my question is could the results from NDSolve be correct
interpolated on the [0-t2] interval insted of [t1 - t2]
interval?
Of course knowing the Mma's interpolating method may be there
was no question.
2. I see every loop operator in Mma (For, While, Do) needs its
body contains expressions divided by semicolons so you can't
get output for example graphics on the screen during loop is
doing. It is very unconvenient in iteractive evaluations. May
be somebody knows any way to solve that problem?
Thank you.
Michael Bogatyriev
Dept. of Automatic Control
Tula State Tech. University
mbog at tulgtu.tula.su