Basics of MATLAB and Beyond

Callbacks are fastest when they are implemented as function calls;do not implement your callbacks as script m-files or as an eval of astring. The reason is that matlab compiles a function the first time itis encountered, whereas m-files and evals are interpreted line by line.The button-style uicontrols (pushbuttons, radiobuttons, and checkboxes)are used by simply clicking on them with the mouse. Othersneed more interaction: you must choose an item from a list (listboxes orpopupmenus) or specify a numeric value (sliders) or type in text (editboxes). We discuss briefly the operation of each of these different kindsof uicontrols.34.2 UIControlsEdit BoxesEdit boxes are designed to read in a piece of typed text. The text insidean Edit box is accessed via the box’s String property:h = uicontrol(’style’,’edit’,’String’,’Hello’);You can change it using the set command:set(h,’string’,’Bye’)or you can click in the box and change it by typing something else. Youcan access what has been typed into an edit box by getting its stringproperty. After typing qwe into the box you can type:>> get(h,’string’)ans =qweNumbers typed into edit boxes remain strings until you convert them tonumbers:>> x = get(h,’string’)x =10.3>> x+1ans =50 49 47 52>> str2num(x) + 1ans =11.3000TextGood GUIs have instructive text that indicates the function of a uicontrol.These can be placed with the text-style uicontrol. In the followingGUIthe “Name:”, “Address:”, and “Sex:” labels are three separateuicontrols of Text style.c○ 2000 by CRC Press LLC