# Definition:Matrix/Order

(Redirected from Definition:Order of Matrix)

## Definition

Let $\sqbrk a_{m n}$ be an $m \times n$ matrix.

Then the parameters $m$ and $n$ are known as the order of the matrix.

### Square Matrix

Let $\mathbf A$ be an $n \times n$ square matrix.

That is, let $\mathbf A$ have $n$ rows (and by definition $n$ columns).

Then the order of $\mathbf A$ is defined as being $n$.

### Column Matrix

Let $\mathbf A$ be an $n \times 1$ column matrix.

Then the order of $\mathbf A$ is defined as being $n$.

### Row Matrix

Let $\mathbf A$ be a $1 \times n$ row matrix.

Then the order of $\mathbf A$ is defined as being $n$.

## Also known as

The order of a matrix can also be referred to as its dimensions, but the term dimension has a different, deeper meaning in linear algebra and this may be a source of confusion.

Some sources refer to the size rather than order, which is acceptable enough.