# 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} = 2**i** + 4**j** +5**k**

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 ...