CODEWITHSUNDEEP
wolfram-mathematica
Eng.Technion
Eng.Technion

Reputation: 11

How to use values computed with NDSolve in Mathematica?

I'm trying to solve one differential equation and use 2 computed values (at specific points) as boundary conditions for a new differential equation. An example:

sys1 = {p''[x] + p'[x] + p[x] == 0,p'[0] == 0,p'[1] ==0};
sol1 = NDsolve[sys1,p[x],{x,0,1}];

Now I want do define sys2 with boundary conditions taken from the solution sol1. I mean it should look like this:

sys2 = {3y''[x] + 7y'[x] - 6y[x] == 0,y[0.3] == p[0.3],y'[1] == p'[1]}

And then we can solve sys2 using NDSolve. I didn't find any clues to how to extract these values from the solution.

Your help would be greatly appreciated.

Upvotes: 0

Views: 1478

Answers (1)

bzu
bzu

Reputation: 1594

You can do:

sol1 = NDSolve[sys1,p,{x,0,1}];
pfun=First[p/.sol1];
pfun[0.3]
pfun'[1]

There is an example in the documentation of InterpolatingFunction for achieving this (http://reference.wolfram.com/language/ref/InterpolatingFunction.html).

Upvotes: 1

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