MATLAB: An Introduction with Applications 5th Edition

Chapter 2

Creating Arrays

The array is a fundamental form that MATLAB uses to store and manipulate data. An array is a list of numbers arranged in rows and/or columns. The simplest array (one-dimensional) is a row or a column of numbers. A more complex array (two-dimensional) is a collection of numbers arranged in rows and columns. One use of arrays is to store information and data, as in a table. In science and engineering, one-dimensional arrays frequently represent vectors, and two-dimensional arrays often represent matrices. This chapter shows how to create and address arrays, and Chapter 3 shows how to use arrays in mathematical operations. In addition to arrays made of numbers, arrays in MATLAB can also be a list of characters, which are called strings. Strings are discussed in Section 2.10.

2.1  CREATING A ONE-DIMENSIONAL ARRAY (VECTOR)

A one-dimensional array is a list of numbers arranged in a row or a column. One example is the representation of the position of a point in space in a three-dimensional Cartesian coordinate system. As shown in Figure 2-1, the position of point A is defined by a list of the three numbers 2, 4, and 5, which are the coordinates of the point.

The position of point A can be expressed in terms of a position vector:

r_A = 2i + 4j +5k

where i, j, and k are unit vectors in the direction of the x, y, and z axes, respectively. The numbers 2, 4, and 5 can be used to define a row or a column vector.

Figure 2-1: Position of a point.

Any list of numbers ...