MATLAB: Matlab 2008b VC++ ODE45

2008bcode45

I am trying to utilize the ODE45 functionality of Matlab in Visual C++ 2010. Searching the Internet, I see that there used to be a file "matlab.hpp" that could be included in a C++ project, but that in R2008b (the version of Matlab I am using), this is not an option. I did try searching Matlab Central for "Matlab 2008 C++ ODE45" and got no hits, so either that was too specific or there really is no solution already posted. If anyone knows how to do this (use ODE45 in C++), I would appreciate the help.

Thanks in advance.

Best Answer

Matlab's ODE45 is a stable and well tested implementation of explicit Runge-Kutta method of Dormand-Prince. It is a 4th order method using an embedded 5th order method for the stepsize control.

This method has been implemented in C directly very often. Look for the terms "RK45" and "Dormand-Prince" in the net, e.g. at www.netlib.org. The C-implementation can be 10 times faster than ODE45.m and I do not see advantages of using the Matlab integrator.

Related Solutions

MATLAB: What interpolation algorithm does the ODE45 function in MATLAB use to evaluate the outputs at the time steps specified in the “tspan” input

The ODE45 function uses the Dormand-Prince DOPRI5(4) method described in the following reference:

 Hairer, Norsett, Wanner, "Solving Ordinary Differential Equations", first edition, vol. I, p. 171 - 179

The interpolation uses slightly differenct coefficients than the implementation in the reference. For details of the implementation refer to the NTRP45 function which can be viewed using the following command:

type('private/ntrp45')

MATLAB: Solving A System of Equations Using ODE45

You have two coupled ODEs for V_p and x. If you want to apply numerical methods (ODE15S, e.g.) for the solution, I don't see a problem.

Maybe starting at t=0 is not a good idea since powers of t appear in the denominator when you solve the first equation for xdot.

Best wishes

Torsten.

Best Answer

Related Solutions

MATLAB: What interpolation algorithm does the ODE45 function in MATLAB use to evaluate the outputs at the time steps specified in the “tspan” input

MATLAB: Solving A System of Equations Using ODE45

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