PDA

View Full Version : Solving differential equations in four variables


Sridatta
Nov16-10, 06:28 PM
I have been trying to solve a problem MATLAb regarding my project and it involves solving set of differential equations involving four variables. It is turning into quite a headache and i was actually wondering if ode45 or ode23 would be sufficient for such a problem.

Problem Structure
----------------------------------
dw/dt = f(z) * dy/dt
w * dx/dt = g(z) * dy/dt
w * dy/dt = f(z) + g(z) * dx/dt + j(z) * dz/dt
w * dz/dt = j(z) * dy/dt

x(0)=0, y(0)=0, z(0)=0, dx/dt(0)=0, dy/dt(0), dz/dt(0)=v

I am supposed to plot 'dw/dz' vs 'z'
----------------------------------

Any insights regarding the problem are extremely welcome.
Thank You,
Sridatta

Bill Simpson
Nov19-10, 09:44 PM
Do you know what f(), g() and j() are?

Different question, what if you just inspected your equations and wrote down (dw/dt)/(dz/dt)=
You need to be cautious with that and think about what it means and what you are doing. I'm not certain that will accomplish your goal.

Sridatta
Nov21-10, 09:10 PM
yeah, f,g,j are complex exponential equations based on 'z' (actually they represent elctromagnetic wave components in a waveguide)