Chapter Contents |
Previous |
Next |

Understanding the Language |

The fundamental data object on which all Interactive Matrix Language commands operate is a two-dimensional (row × column) numeric or character matrix. By their very nature, matrices are useful for representing data and efficient for working with data. Matrices have the following properties:

- Matrices can be either numeric or character. Elements of a numeric matrix are stored in double precision. Elements of a character matrix are character strings of equal length. The length can range from 1 to 32676 characters.
- Matrices are referred to by valid SAS names. Names can be from 1 to 8 characters long, beginning with a letter or underscore, and continuing with letters, numbers, and underscores.
- Matrices have dimension defined by the number of rows and columns.
- Matrices can contain elements that have missing values (see the section "Missing Values" later in this chapter).

The dimension of a matrix is defined by
the number of rows and columns it has.
An *m* ×*n* matrix has *mn* elements
arranged in *m* rows and *n* columns.
The following nomenclature is standard in this book:

- 1 ×
*n*matrices are called*row vectors*. -
*m*×1 matrices are called*column vectors*. - 1 ×1 matrices are called
*scalars*.

Chapter Contents |
Previous |
Next |
Top |

Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.