Page 70 - A Guide to MATLAB for Beginners and Experienced Users

Data Classes 51

You can also use semicolons to separate a string of commands when you are
interested only in the output of the final command (several examples appear
later in the chapter). Commas can also be used to separate commands without
suppressing output. If you use a semicolon after a graphics command, it will
not suppress the graphic.

➱ The most common use of the semicolon is to suppress the printing of
a long vector, as indicated in Chapter 2.

Another object that you may want to suppress is MATLAB’s label for the
output of a command. The command disp is designed to achieve that; typing
disp(x) will print the value of the variable x without printing the label and
the equal sign. So,
>>x=7;
>> disp(x)
7
or

>> disp(solve(’x + tan(y) = 5’, ’y’))
-atan(x-5)

Data Classes

Every variable you define in MATLAB, as well as every input to, and output
from, a command, is an array of data belonging to a particular class.Inthis
book we use primarily four types of data: floating point numbers, symbolic
expressions, character strings, and inline functions. We introduced each of
these types in Chapter 2. In Table 4–1, we list for each type of data its class
(as given by whos ) and how you can create it.
Type of data Class Created by
Floating point double typing a number
Symbolic sym using sym or syms
Character string char typing a string inside single quotes
Inline function inline using inline

Table 4-1
You can think of an array as a two-dimensional grid of data. A single number
(or symbolic expression, or inline function) is regarded by MATLAB as a 1 × 1