Help with MATLAB GUI to Model Simple Harmonic Motion

[adelanteh]

[Matlab virgin here]

I am in great need of some help. My task is to create GUI app to model simple harmonic motion of a spring with a mass attached to it. The requirements are to have the user be able to change every parameter of the equation:
my'' + cy' + ky' = f(t)

The m, c, k, and f are the usual constants - mass, spring constant and so on. Upon changing these parameters the user should be able to see a live visual of the spring moving and a graph for an analytical understanding of the motion through some specified time of action. By default the time of action should be about 10sec then the simulation stops and the parameters could be changed.

This is what I've done so far:
Made the complete GUI app. This includes all necessary user interfacing, the "live" graph, and spring animation.

Now what I need some help on is the relate all the user inputs to the formula to get the simulation.
Yea, I know I haven't done much because the GUI was the easy part, but I did get the "grid on" and "grid off" buttons to work Other than that, I pretty much didnt do any Callbacks and so on to help analyze the data.

Can someone help me get started?

http://linuxfreak87.googlepages.com/HarmonicSpring.m <-- m-file
http://linuxfreak87.googlepages.com/HarmonicSpring.fig <--fig file

Using Matlab 2009
I don't have so much time.
it's beter to mail me on s.hosseini1365@gmail.com
thanks to all.

 

[NateD]

[/quote]It's really hard to help you without seeing the code, but I can give you a few tips. First, you need to create a function that takes in the parameters (m, c, k, f) and returns the solution to the differential equation. This could be done using one of Matlab's ODE solvers such as ode45. Once you have the function that returns the solution, you need to set up the GUI so that when the user changes a parameter it updates the plot. To do this you need to use callbacks. A callback is a function that is executed when an event occurs (in this case when a parameter is changed). This can be done by setting the 'Callback' property for each of the UI elements (e.g. sliders, text boxes, etc.) to the name of a function. This function should take the input from the UI element, update the plot accordingly, and then call the ODE solver with the new parameters. Hopefully this helps get you started. Good luck!