Engineering Fundamentals: An Introduction to Engineering, 4th ed.c

Note that in MATLAB, the elements of the matrix are enclosed in brackets [ ]and are separated

by blank space, and the elements of each row are separated by a semicolon ;as shown in Figure 15.2.

In Section 18.5, we will discuss matrix algebra in more detail. If you do not have an ade-

quate background in matrix algebra, you may want to read Section 18.5 before studying the

MATLAB examples that deal with matrices.

The format,disp,and fprintfCommands

MATLAB offers a number of commands that you can use to display the results of your calcu-

lation. The MATLAB formatcommand allows you to display values in certain ways. For

example, if you define x = 2/3, then MATLAB will display x = 0.6667. By default,

MATLAB will display four decimal digits. If you want more decimal digits displayed, then you

type format long. Now, if you type xagain, the value ofxis displayed with 14 decimal

digits, that is x = 0.66666666666667. You can control the way the value ofxis displayed

in a number of other ways, as shown in Table 15.2. It is important to note that the format

command does not affect the number of digits maintained when calculations are carried out by

MATLAB. It only affects the way the values are displayed.

The dispcommand is used to display text or values. For example, given x = [1 2 3

45],then the commanddisp(x)will display 12345. Or the commanddisp

('Result = ')will display Result =. Note that the text that you want displayed must

be enclosed within a set of single quotation marks.

The fprintfis a print (display) command that offers a great deal of flexibility. You can

use it to print text and /or values with a desired number of digits. You can also use special

15.1 MATLAB —Basic Ideas 465

TABLE 15.2 The Format Command Options

How the Result of

MATLAB Command x 2/3 is Displayed Explanation

format short 0.6667 Shows four decimal

digits-default format.

format long 0.66666666666667 Shows 14 decimal digits.

format rat 2/3 Shows as fractions of whole

numbers.

format bank 0.67 Shows two decimal digits.

format short e 6.6667e-001 Shows scientific notation

with four decimal digits.

format long e 6.666666666666666e-001 Shows scientific notation

with 14 decimal digits.

format hex 3fe5555555555555 Shows hexadecimal output.

format +  Shows , , or blank based

on whether the number is

positive, negative, or zero.

format compact It suppresses the blank lines

in the output.

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