can I enter a single variable function in edit text in GUI?

I'm currently doing a GUI for a 3D function grapher and I'm having trouble with the edit text callback. I want user to enter the parametrized function in terms of t in 3 different edit text for P, Q, R parts but I don't know how to do the callback.

Answer 1

[Image Analyst]

I don't know why an edit text would need a callback. I never use one. Since the callback never gets called until the edit text box loses focus, for example by clicking on a button or scrollbar, then why not just put the "UpdatePlot" function into it's own function and have things like scrollbars and buttons call it. I see no compelling reason for an edit text box to have a callback.

[Sean de Wolski]

@IA, I use the edit text box callback to validate the input (e.g. integer between 0 and 10), but that's about it...

[Matthew]

So what should I use instead if I want user to enter the function on GUI?

[Sean de Wolski]

I would use a listbox with a selection of acceptable functions.

[Matthew]

What if I want user to enter a function of t which t is predefined in the script, what should I use?

[Walter Roberson]

handle_for_user_function = str2fun(['@(t) ', TextUserEntered]);

[Image Analyst]

Sean, FYI: Yair just talked about edit box validation: http://undocumentedmatlab.com/blog/editbox-data-input-validation/