## `linalg::multRow` -- multiply rows with a scalar

#### Introduction

`linalg::multRow``(A, r, s)` returns a copy of the matrix A resulting from A by multiplying the r-th row of A with the scalar s.

#### Call(s)

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

#### Parameters

`A` | - | an m x n matrix of a domain of category `Cat::Matrix`
`r` | - | the row index: a positive integer <= m
`r1..r2` | - | a range of row indices (positive integers <= m)
`list` | - | a list of row indices (positive integers <= m)

#### Returns

a matrix of the same domain type as `A`.

#### Related Functions

`linalg::addCol`, `linalg::addRow`, `linalg::multCol`

#### Details

- `linalg::multRow``(A, r1..r2, s)` returns a copy of the matrix `A` obtained from `A` by multiplying those rows whose indices are in the range `r1..r2` with the scalar `s`.
- `linalg::multRow``(A, list, s)` returns a copy of the matrix `A` obtained from matrix `A` by multiplying those rows whose indices are contained in `list` with the scalar `s`.
- The scalar `s` is converted into an element of the component ring of the matrix `A`. An error message is returned if the conversion fails.

#### Example 1

We define the following matrix:

    >> A := matrix([[1, 2, 3], [4, 5, 6], [7, 8, 9]])

                                   +-         -+
                                   |  1, 2, 3  |
                                   |           |
                                   |  4, 5, 6  |
                                   |           |
                                   |  7, 8, 9  |
                                   +-         -+

and illustrate the three different input formats for `linalg::multRow`:

    >> linalg::multRow(A, 2, -1)

                                 +-            -+
                                 |   1,  2,  3  |
                                 |              |
                                 |  -4, -5, -6  |
                                 |              |
                                 |   7,  8,  9  |
                                 +-            -+

    >> linalg::multRow(A, 1..2, 2)

                                  +-           -+
                                  |  2,  4,  6  |
                                  |             |
                                  |  8, 10, 12  |
                                  |             |
                                  |  7,  8,  9  |
                                  +-           -+

    >> linalg::multRow(A, [3, 1], 0)

                                   +-         -+
                                   |  0, 0, 0  |
                                   |           |
                                   |  4, 5, 6  |
                                   |           |
                                   |  0, 0, 0  |
                                   +-         -+

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