# linalg::row

Extract rows of a matrix

### Use only in the MuPAD Notebook Interface.

This functionality does not run in MATLAB.

## Syntax

```linalg::row(`A`, `r`)
linalg::row(`A`, `r1 .. r2`)
linalg::row(`A`, `list`)
```

## Description

`linalg::row(A, r)` extracts the r-th row vector of the matrix A.

`linalg::row(A, r1.. r2)` returns a list of row vectors whose indices are in the range ```r1.. r2```. If ```r2< r1``` then the empty list `[]` is returned.

`linalg::row(A, list)` returns a list of row vectors whose indices are contained in `list` (in the same order).

## Examples

### Example 1

We define a matrix over :

```A := Dom::Matrix(Dom::Rational)( [[1, 1/5], [-3/2, 5], [2, -3]] )```

and illustrate the three different input formats for the function `linalg::row`:

`linalg::row(A, 2)`

`linalg::row(A, [2, 1, 3])`

`linalg::row(A, 2..3)`

## Parameters

 `A` An m×n matrix of a domain of category `Cat::Matrix` `r` The row index: a positive integer less or equal to m `r1 .. r2` A range of row indices (positive integers less or equal to m) `list` A list of row indices (positive integers less or equal to m)

## Return Values

Single row vector or a list of row vectors; a row vector is a 1×n matrix of category `Cat::Matrix``(R)`, where R is the component ring of `A`.