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

15.2 Using MATLAB Built-in Functions 475

TABLE 15.10 MATLAB’s Logical Operators

Logical

Operator Symbol Description

and & TRUE, If both conditions are true

or | TRUE, If either or both conditions are true

not  FALSE, If the result of a condition is TRUE, and

TRUE, If the result of a condition is FALSE

exclusive or xor FALSE, If both conditions are TRUE or both

conditions are FALSE, and TRUE, If either

condition is true

any TRUE, If any element of vector is nonzero

all TRUE, If all elements of vector is nonzero

Note that in the preceding example, the index is the integer i and its start-value is 1, it is in-

cremented by a value of 1, and its end-value is 5.

The whileLoop Using the whileloop, you can execute a line or a block of code until a specified

condition is met. The syntax of a whileloop is

while controlling-expression

a line or a block of your computer code

end

With the whilecommand, as long as the controlling-expression is true, the line or a block of

code will be executed. For the preceding example, the MATLAB code using the whilecommand

becomes:

x = 22.0;

while x <= 24.00

y=x^2+10;

disp([x',y'])

x = x + 0.5;

end

In the preceding example the symbol denotes less than or equal to and is called a rela-

tional or comparison operator. We will explain MATLAB’s logical and relational operators next.

Using MATLAB Logical and Relational Operators

In this section, we will look at some of MATLAB’s logical operators. These are operators that

allow you to test various conditions. MATLAB’s logical operators and their descriptions are

shown in Table 15.10.

MATLAB also offers relational or comparison operators that allow for the testing of rela-

tive magnitude of various arguments. These relational operators are shown in Table 15.11.

The Conditional Statements — if, else

When writing a computer program, sometimes it becomes necessary to execute a line or a block

of code based on whether a condition or set of conditions is met (true). MATLAB provides if

and elsecommands for such situations.

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