Oriente Medio

With MATLAB 7 the MATLAB user interface has again undergone extensive modernization, which really makes using this tool substantially easier to use, both in the interactive mode and for developing programs (see Section 1.7).

In this section these capabilities will be elucidated further. Of course, we cannot give the reader a complete overview of the manifold capabilities of the desktop. That would go beyond the scope of this book.

Just a few of the basic principles will be discussed.

Menus and Shortcuts

Basically, the most varied capabilities involve addressing or setting up the MATLAB user interface (see Fig.1.1).

In general, the functions of the user interface can be selected by

choosing the appropriate menu entry using the mouse,

choosing the appropriate icons in the icon toolbar using the mouse, so-called shortcuts, and

selection within a context menu (i.e., by right-clicking the mouse in the current working window).

Beyond this, many functions can also be called by entering appropriate MATLAB commands in the command window.

The first two possibilities for choosing functions are standard in every Windows application and need not be elaborated further here.

As for shortcuts, a distinction must first be made between the so-called keyboard shortcuts and MATLAB shortcuts. Keyboard shortcuts are stan-dard in every Windows application. They are key combinations that set up a given functionality in the user interface. The best known and most used representatives of this class are Control-C and Control-V for copying and pasting data between two Windows applications with the aid of the Win-dows interface. In the MATLAB command window, for example, the key combinations Control-P and Control-N replace the arrow keys↑ and

↓ for reconstructing commands, as mentioned in Section 1.2.1.

With MATLAB shortcuts, on the other hand, MATLAB commands can be combined and later called in a single step with a mouse move-ment. Shortcuts are defined using the so-called shortcut editor, which can be called up with the start button (see Fig. 1.1, item 7) in the menu Shortcuts - new shortcut.... Based on an option chosen within the editor, the defined shortcuts can either be anchored in the start-button menu or integrated as icons in the shortcut toolbar (item 6).

FIGURE 1.21 Shortcut toolbar with the self-defined shortcut “clear screen.”

Fig. 1.21 shows a segment of Fig. 1.1 with an icon integrated into the shortcut toolbar for initiating the often-used MATLAB command clc, with which the command window can be cleared.

Likewise, a fast way of selecting functionalities in the MATLAB interface is to right-click the mouse on the available context menu in the corresponding working window (context!).

Right-clicking the mouse then opens a context related pulldown menu in which functions can be selected by left-clicking the mouse.

FIGURE 1.22 Context menu in the command-history window.

As an example, Fig. 1.22 shows a pulldown menu generated by right-clicking the mouse in the command-history window.

In this menu it is now possible to select what is to be done with it or with the previously selected commands in the history window. For example, they can be executed again by choosing the menu item Evaluate Selection.

Tab Completion

An interesting possibility for making MATLAB easier to use in the interac-tive mode is the tab completion technique. Variable names, function names, file names, and structures, as well as graphic handles, can be quickly and efficiently created (in the command window) using the tab key on the PC keyboard.

To do this, the functionality is first initiated by choosing the appro-priate box in the menu File- Preferences ... under Command-Window- Keyboard ....

Then, for example, you can type in the beginning of the function name in the command window and press the tab key.

Fig. 1.23 shows the result of this operation after entering plo, the first letters of many plot functions.

The desired function can be selected in the pulldown menu. This is then entered in the command window. The prerequisite for operation of this mechanism is, of course, that MATLAB can also find the corresponding function or variable names (i.e., that these names are entered in the current search path or in the current workspace).

FIGURE 1.23 Tab-completion function.

History and Monitoring Functions

The history mechanism, which was already introduced in Section 1.2.1, is of special interest for the MATLAB user on returning to the interactive mode after a long time. The history functionality allows the user to reconstruct commands from the current session or from earlier sessions and to reuse them rapidly.

All the commands set in the course of the session are listed in the command-history window. These commands can then be reconstructed as shown in Section 1.2.1.

Beyond this, shortcuts (see above) or m-files (see Section 1.6) can easily be created from the commands collected in the command-history window.

This is most easily done by selecting the relevant commands and by choosing the corresponding function in the context menu (right mouse click).

The search for old commands has been further simplified in MATLAB 7.

Instead of searching in the command window, the reader can also enter the initial letter of a command in the command-history window. (Click on the window and type in the letters.) The window jumps to the next command with this initial letter. Whole parts of commands can also be found via the menu entry Edit - Find in the user interface.

For keeping a record of the entire session, not just the commands but also the responses of MATLAB, the diary function is available. This is chosen by entering

>> diary(filename)

From this point in time a record will be kept in ASCII format of the MATLAB session in a file with this name. The file is created in the current directory.

For example, if the session is saved in a file named session 11.09.2005.txtwith

>> diary ('session 11.09.2005.txt')

it will be saved until this mechanism is terminated with the following command:

>> diary off

Configuration Capabilities

In Sections 1.2 and 1.2.1 it has already been pointed out that the interface shown in Fig. 1.1 does not in the least have a unified structure.

In fact, the user has many options available for molding the appearance of the interface according to his needs. The docking mechanism has already been described in Section 1.2.1. With it, partial windows in the interface can be docked and again be erased. Of course, the layout can also be varied by pulling with the mouse. Color arrangement, font, and many other aspects can be controlled via Preferences. Once the layout is changed, it can be saved using the menu entry Desktop - Save layout ....

It is left to the reader to create a suitable appearance for the layout of the MATLAB working interface.