## Signal Terminology

This section defines important Communications Toolbox™ terms related to matrices, vectors, and scalars, as well as frame-based and sample-based processing.

### Matrices, Vectors, and Scalars

This document uses the unqualified words scalar and vector in ways that emphasize the number of elements in a signal, not its strict dimension properties:

• A scalar signal contains a single element. The signal could be a one-dimensional array with one element, or a matrix of size 1-by-1.

• A vector signal contains one or more elements, arranged in a series. The signal could be a one-dimensional array, a matrix that has exactly one column, or a matrix that has exactly one row. The number of elements in a vector is called its length or, sometimes, its width.

In cases when it is important for a description or schematic to distinguish among different types of scalar signals or different types of vector signals, this document mentions the distinctions explicitly. For example, the terms one-dimensional array, column vector, and row vector distinguish among three types of vector signals.

The size of a matrix is the pair of numbers that indicate how many rows and columns the matrix has. The orientation of a two-dimensional vector is its status as either a row vector or column vector. A one-dimensional array has no orientation – this is sometimes called an unoriented vector.

A matrix signal that has more than one row and more than one column is called a full matrix signal.