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Topic: Differential equation and ode45 or ode15i
Replies: 10   Last Post: Jan 28, 2014 3:14 AM

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Torsten

Posts: 1,449
Registered: 11/8/10
Re: Differential equation and ode45 or ode15i
Posted: Jan 27, 2014 8:22 AM
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"shatrah " <shatrah1978@gmail.com> wrote in message <lc35in$d3g$1@newscl01ah.mathworks.com>...
> dq/dz=dy/dz+q
> dy/dz=z*y
> ds/dz=dy/dz+dq/dz
>
> y=10, dy/dz=0 for z=0
> z=15, dz/dz=0 for z=0
> q=11, dq/dz=0 for z=0
>
>
> 1- how can solve this problem ? using ode45 or ode15i
>
>
> if i need to use ode45 can make like this
>
> dy(1)=dy(2)+y(1)
> dy(2)=y(2)*z
> dy(3)=dy(2)+dy(1)
>
>
> as a function filw ?
>
> Thanks


function dy = test(z,y)
dy = zeros(3,1); % a column vector
dy(1)=z*y(2)+y(1);
dy(2)=z*y(2);
dy(3)=2*z*y(2)+y(1);

But I don't understand your initial conditions:
y=10, dy/dz=0 for z=0
z=15, dz/dz=0 for z=0
q=11, dq/dz=0 for z=0

Best wishes
Torsten.



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