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Topic: simultaneous differential equations
Replies: 1   Last Post: Mar 15, 2013 9:49 AM

 Torsten Posts: 1,717 Registered: 11/8/10
Re: simultaneous differential equations
Posted: Mar 15, 2013 9:49 AM

"Bonny Nguyen" wrote in message <khv7qr\$s1f\$1@newscl01ah.mathworks.com>...
> Dear everybody,
> I have a problem when compute simultaneous differential equations follow that:
> A, B, C, D are variable M =[m11 m12 m13 m14; m21... m24; m31..m34; m41...m44] is matrix , and also m11, m12.... m44 are number matrix
> eqution:
> dA/dz = m11A + m12B + m13C + m14D
> dB/dz = m21A + m22B + m23C + m24D
> dC/dz = m31A + m32B + m33C + m34D
> dD/dz = m41A + m42B + m43C + m44D
> in this case, z=1:0.1:301
> for instance, m11=K11*cos((2*pi/5e-7)*z)
> K11=constant
>
> Thank you so much
>
> Sincerely,

You can use one of the ODE integrators (ode45, ode15s,...),
interprete z as t in the notation of the integrators and set up your problem in a standard way.
Take a look at the examples provided.
Or what exactly is your problem ?

Best wishes
Torsten.