1
vote
0answers
49 views

Speeding up NDSolve for system of differential equations

I am wondering if there is a way to speed up this function that solves a system of ordinary differential equations with NDSolve? Thus far I've tried specifying a few different methods such as LSODA, ...
0
votes
0answers
22 views

Pass model parameters to NDSolve'Reinitialize

I am wondering if there is a way to pass parameter values during the NDSolve'Reinitialize step of the NDSolve process? I've read that one way to possibly speed up repeated calls to NDSolve is to ...
2
votes
2answers
113 views

Find minimum value of function which calls NDsolve [duplicate]

I have defined a function which takes a coefficient for a differential equation as an argument, solves the differential equation with NDSolve, and returns the value of the solution at time t=10. I can ...
4
votes
1answer
135 views

Ordinary differential equation invloving the function composition

I want to solve the following function: DSolve[(A1*Exp[B1*f[x]] + A2*Exp[B2*f[x]])*f'[x] == A1*Exp[B1*x] + A2*Exp[B2*x], f[x], x] And this is what I get as an ...
4
votes
1answer
171 views
4
votes
0answers
183 views

Using FindFit to fit nonlinear ODE parameters, subject to a constraint (an inverse problem)

Similar to this post I am finding that constraints tend to make FindFit poor at finding a good fit. However, unlike the previous post, the constraints are required ...
3
votes
1answer
185 views

Distance between two functions satisfying a constraint

My problem is that I have two functions that are described as follows: ...
4
votes
1answer
248 views

Using a user defined NormFunction in FindFit or NDSolve

I would like to use a different norm instead of the 2-norm in FindFit (Mathematica 9). For example, instead of using $$\sqrt{\sum (x_{\mathrm{model}} - ...
1
vote
1answer
414 views

Optimizing the fitting of Ordinary Differential Equation(NDsolve) involving interpolation functions

I am a newbie to this forum. I am trying to use NDsolve to solve some ODEs involving the interpolation function. Then, I will compare the fitted curve and data to determine the ODE coefficients. ...
-3
votes
1answer
1k views

How can Mathematica solve this set of differential equations? [closed]

I'm trying to solve this set of non linear differential equations, but apparently it won't solve. I really tried all the tweaks I could think of. Still no progress... So now I turn to you, can you ...
2
votes
2answers
773 views

optimization problem with NDSolve

I want to minimize the function fcc. When fcc is calculated for a specified point the answer is correct: ...
2
votes
1answer
553 views

Optimizing a function involving NDSolve results in error messages

I want to minimize a function f with NMinimize but an error occurs that says: ...