Center for Interdisciplinary Research and Consulting

This document explains how to get started with MATLAB on computer systems at UMBC. It will not tell you how to use MATLAB, but rather, where to find the appropriate information to learn more.

If you are interested in how to use MATLAB, come to free software workshops offered by CIRC. They are held during Fall and Spring semesters on Wednesdays during Free Hour (12noon-01pm) in room ENGR 122, an instructional computer lab in the Engineering Building at UMBC. The workshops on MATLAB form a sequence that covers topics from a basic introduction to efficient simulations.

For a more thorough introduction with guided homework projects, consider the official 2-credit class MATH 426 Introduction to Math Software Packages: MATLAB that the Department of Mathematics and Statistics offers in Summer and Winter semesters.

MATLAB's name originates from **Mat**rix **Lab**oratory, since it
was originally written as a teaching tool to support an introductory
linear algebra class (like MATH 221 at UMBC).
Since that first version, it has been extended and upgraded to
be one of the most versatile and popular packages for numerical computations
and graphing. It is widely used in industrial companies, government agencies,
and educational institutions for rapid prototyping and teaching. Its main
popularity roots in its intuitive interactive interface combined with reliable
numerical algorithms and professional graphics capabilities.

For the official description of MATLAB, check out http://www.mathworks.com, the webpage of the MathWorks, Inc., maker of MATLAB.

UMBC maintains a campus licences for MATLAB and many of its toolboxes. The most efficient way to run MATLAB is to use a lab PC and run it locally. You may also run it remotely on several of the gl systems.

Under Windows 7 or 8, click on the
Windows Start Orb to open the Start Menu, type "`matlab`" to
search for the program, then click on the version you want to run. MATLAB might
remember whether you had other windows open at the end of your previous
session, so the Help browser (which might even open with the page you last
visited) and other windows may open again.

At present (8/2013), in the UMBC computer labs, MATLAB starts up in a folder similar to \\profile.ad.umbc.edu\Userfiles$\username\My Documents\MATLAB. This directory is visible in the "Current Folder Toolbar" above the other desktop windows and below the "Toolstrip".

As an example of how to create a directory structure for your current
project, here are instructions that a student in Math 426 can use to to
organize her files for that course. First, create a folder for this class by
entering "`mkdir Math426`" on the MATLAB command line
(the window with the `>>` prompt),
and then change into it by entering "`cd Math426`".
Next, create a directory for each homework by
entering "`mkdir Homework1`" and change to it by entering
"`cd Homework1`".
Check what the Current Folder Toolbar says or enter
"`pwd`" (print working directory) at the MATLAB command line.

Under Linux, you need to get a command window (shell) first. Then, enter
"`matlab`" at the command window prompt (and press return).
To get more information on command line options, enter
"`matlab -h`" at the Linux command prompt,
which gives information about possible command line arguments,
but does not start MATLAB. MATLAB might remember
whether you had other windows open at the end of your previous session, so the
Help browser and other windows may open again.

Under Linux, it makes more sense to change directory first at
the Linux command line and before starting MATLAB, using the
Linux commands "`mkdir`" and "`cd`" (and "pwd" and "ls" to
inquire). Then, start MATLAB in your desired directory which will make all
files associated with your project accessible.

Usually, it is most effective and convenient to run MATLAB locally, in particular for interactive work, but there are a number of reasons why you might want to run MATLAB remotely across a network. For instance, your local machine may not have MATLAB installed, or your local machine may not have sufficient memory for your task. In these cases, running MATLAB remotely may be worthwhile.

On your Linux terminal, enter
"`ssh -X username@linux.gl.umbc.edu`",
where `username` is your UMBC username.
The `-X` argument enables graphics.
Once you are connected to the UMBC server, enter "`matlab`"
at the Linux command prompt.

Sometimes the performance of remote graphics is frustratingly slow, in which
case you may want to start MATLAB (i) without its desktop and (ii) without
any graphics (including the splash screen); this can be accomplished by using
"`matlab -nodesktop -nodisplay`". To get more information on command
line options, enter "`matlab -h`".

Under the Microsoft Windows
operating systems, Linux X Windows programs can be used for remote access. For
a description on running X Windows programs remotely, see that section under
the General
Productivity portion of the High Performance Computing Facility (HPCF) webpage. There, you will find
instructions which include installing PuTTY (for the remote SSH connection) and
Xming (for remote graphics). If you do not wish to use graphics, perhaps
because the connection is slow,
you may want to start MATLAB (i) without its desktop and (ii) without
any graphics (including the splash screen); this can be accomplished by using
"`matlab -nodesktop -nodisplay`". To get more information on command
line options, enter "`matlab -h`".

The maya cluster is accessible to individuals with an account through HPCF. Connecting to maya is done remotely.

Usually, it is most effective and convenient to run MATLAB locally, in particular for interactive work, but there are a number of reasons why you might want to run MATLAB remotely across a network. For instance, your local machine may not have MATLAB installed, or your local machine may not have sufficient memory for your task. In these cases, running MATLAB remotely may be worthwhile.

On your Linux terminal, enter
"`ssh -X username@maya.rs.umbc.edu`",
where `username` is your UMBC username.
The `-X` argument enables graphics.
Once you are connected to maya, enter "`matlab`"
at the Linux command prompt.

Sometimes the performance of remote graphics is frustratingly slow, in which
case you may want to start MATLAB (i) without its desktop and (ii) without
any graphics (including the splash screen); this can be accomplished by using
"`matlab -nodesktop -nodisplay`". To get more information on command
line options, enter "`matlab -h`".

Under the Microsoft Windows
operating systems, Linux X Windows programs can be used for remote access. For
a description on running X Windows programs remotely, see that section under
the General
Productivity portion of the High Performance Computing Facility (HPCF) webpage. There, you will find
instructions which include installing PuTTY (for the remote SSH connection) and
Xming (for remote graphics). If you do not wish to use graphics, perhaps
because the connection is slow,
you may want to start MATLAB (i) without its desktop and (ii) without
any graphics (including the splash screen); this can be accomplished by using
"`matlab -nodesktop -nodisplay`". To get more information on command
line options, enter "`matlab -h`".

A detailed description along with examples of how to run MATLAB on maya is provided on the HPCF webpage. The cluster maya is meant for batch processing, so this is the preferred mode of running MATLAB for production runs.

There are several ways to get help from MATLAB. MATLAB's internal documentation, described in the next section, is very useful. Additionally, searching the internet, e.g., via google.com, has recently increasingly proven to be a very useful way to debug problems. While searching the internet, you will discover several online forums for posting and answering questions about MATLAB.

The command window is the one with MATLAB's "`>>`" prompt. Two
MATLAB commands can give you help inside this window (without starting any
other windows, etc.), which might be important if you use MATLAB remotely.
Also, the help accessible in this way would work for functions and scripts
written by you.

The command "`help functionname`" displays the help on the function
called "`functionname`". This syntax works for any function that is be
in the current directory or on the search path. Use "`which
functionname`" to find out exactly which function on the search path is
being called. The "`help`" command works by displaying the comments at
the beginning of the m-file with name functionname.m up to the first blank line
or the first line of code.

If you do not know the name of the function,
you can search for it using the "`lookfor keyword`" command, which
searches for "`keyword`" in the first line following the function declaration (called the H1 line) of all m-files on
the search path. Use "`help lookfor`" for an explanation of how to expand this search to the entire first comment block of each m-file.

If you use MATLAB on your local machine, the Help browser is available to
access the complete documentation in many different ways, including by topic
from the table-of-contents of the manuals, by name of function, or by
(full-text) keyword search. There are many different ways to start this Help
browser, including several under the Help menu of the desktop or by clicking
the question mark "?" near the top of the desktop. Or from the prompt
"`>>`" in the command window enter "helpbrowser". You could also say
helpdesk, helpwin, or doc, which might differ from each other by the page
displayed in the Help browser upon opening. Try out what seems most useful to
you. Note that MATLAB might remember which page you looked at last in your
previous session, so it is useless to predict exactly what will happen under
various circumstances.

Besides starting the Help browser and then using its features to find what
you want, you can directly open the Help broswer for a particular function
functionname by entering "`doc functionname`". It is sometimes
necessary to issue this command twice to get the desired effect, though. If the
Help browser is not open yet, it is started up, or if it is already open, the
page displayed is changed. The help content via entering "`doc
functionname`" is similar, and in some cases identical, to that obtained
via entering "`help functionname`", but the former command often has
more information and additional examples; and, especially for graphics
commands, you will find full examples which would not be available by using
"`help`" in the command window alone. However, sometimes the more
compact information inside the command window has its advantages. Try
comparing the information available from "`help plot`" with "`doc
plot`".

The best way to get started is to read MATLAB's internal documentation via
the Help browser. From within MATLAB, you can open the Help browser by typing
"`doc`" at the prompt of the command window.

Help opens with tabs for Installation and Release Notes, and with available help for the main MATLAB package, as well as all of the installed Toolboxes.

An excellent way to learn about MATLAB's features and how to use them is to study the "Getting Started with MATLAB" guide. To access the guide, click on the "Matlab" link and then click on the first tab under called "Getting Started".

The "Getting Started with MATLAB" guide explains the philosophy of MATLAB (including the features of the desktop environment) and walk you through the most basic commands. You should try out commands in the command window while reading the Getting Started guide. The guide has several tutorials including the "2-D and 3-D Plots" tutorial which explains the use of graphics commands. The "Programming and Scripts" tutorial explains how write Matlab scripts, including the use of loops and conditional statements.

In addition to this help inside of MATLAB, MathWorks also makes the documentation available online. Try an internet search like "matlab handle graphics", and one of the first results will be MathWorks' online documentation.