Lab 30

GUI Components

CS211 Lab Policy:

• This lab exercise will not be graded.
• Submit as much as you have completed before the end of the lab period in which it is assigned.
• If you do not finish this lab work, it is to your advantage to finish it outside of class. Please re-submit your finished work to the course web site.
• You may receive help from anyone in completing this lab.
• You may not submit another student's code as part of your lab.

Instructions:

For this assignment you will create a GUI program, Lab30.m, that allows a user to investigate the curve cos(x+A) + sin(B*x) as A varies from [0, 2pi] and B varies from [-10, +10]. The curve should be plotted in the x-range [-10, +10]. Your interface should include the following components:

• A static text component that shows the current equation (with appropriate values for A and B filled in).
• An axes component that plots the curve.
• Two slider bars that allow the user to vary the values of A and B. The slider bars should be labeled with appropriate static text components.

An example program GUI is shown in the figure below.

Helpful suggestions:

• Make sure you give each component a descriptive Tag property so that its callback function and object handle will have a meaning name.
   
• Make sure you set the Units property of all components to 'normalized'.
   
• Each time you change the value of A or B the curve will change. The default behavior for MATLAB is to adjust the y-axis limits based on the current curve's y-values. This makes it difficult to visualize the changes to the curve as A and B change. You need to hold the y-axis constant as the curve changes. To do this, set the 'YLim' property for the axes component to [-2 2] every time you plot the curve.
   
• Set initial default values for A and B in your *_OpeningFcn() function. In addition, plot the initial view of the curve and update the title.
   
• Each time a slider bar changes, your code needs to redraw the curve appropriately.
   
• Since the *_OpeningFcn() function and both the slider bars must do the same work, consider creating a single function to perform the work of updating the window. Then you can call this function from the *_OpeningFcn() function and the slider callback functions.

Turn-in:

Submit your Lab30.m and Lab30.fig file.