Drexel dragonThe Math ForumDonate to the Math Forum



Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.


Math Forum » Discussions » Software » comp.soft-sys.matlab

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

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
shatrah

Posts: 11
Registered: 1/26/14
Re: Differential equation and ode45 or ode15i
Posted: Jan 27, 2014 9:23 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

"Torsten" wrote in message <lc5mi0$n5t$1@newscl01ah.mathworks.com>...
> "shatrah " <shatrah1978@gmail.com> wrote in message <lc35in$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.


Dont look at my initial conditions , its just example ,
my question can put like this dy(1)=dy(2) ??




Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2014. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.