# Crate vectrix[−][src]

## Expand description

This crate provides a stack-allocated, constant-size `Matrix<T, M, N>`

type implemented using const generics.

### 🚀 Getting started

Add the following to your Cargo manifest.

```
[dependencies]
vectrix = "0.2"
```

`no_std`

is also supported by disabling the default std feature.

```
[dependencies]
vectrix = { version = "0.2", default-features = false, features = ["macro"] }
```

### 🤸 Usage

#### Types

The base `Matrix<T, M, N>`

type represents a matrix with `M`

rows and `N`

columns. This type is a backed by an array of arrays. The data is stored in
column-major order. Some convenient aliases are provided for common
matrices, like vectors.

`Matrix<T, M, N>`

→ a generic matrix type with`M`

rows and`N`

columns.`Vector<T, M>`

→ a column vector with`M`

rows.`RowVector<T, N>`

→ a row vector with`N`

columns.

#### Macros

Macros are provided for easy construction of the provided types. These
macros will also work in `const`

contexts.

The `matrix!`

macro can be used to construct a new `Matrix`

of any size.

```
let matrix = matrix![
1, 3, 5;
2, 4, 6;
];
```

In the above example `matrix`

is a `Matrix<_, 2, 3>`

type, having 2 rows and
3 columns.

The `vector!`

and `row_vector!`

macros can be used to to construct
vectors.

```
let vector = vector![1, 3, 3, 7];
// ^^^^^^ type `Vector<_, 4>`
assert_eq!(vector, matrix![1; 3; 3; 7]);
let vector = row_vector![1, 3, 3, 7];
// ^^^^^^ type `RowVector<_, 4>`
assert_eq!(vector, matrix![1, 3, 3, 7]);
```

#### Constructors

Commonly used constructors are listed below.

`::zero()`

→ constructs a new matrix filled with`T::zero()`

.`::identity()`

→ constructs a new identity matrix.`::repeat(..)`

→ constructs a new matrix filled with the provided value.`::repeat_with(..)`

→ constructs a new matrix filled with values computed by the provided closure.`::from_iter(..)`

→ constructs a new matrix from an iterator.`::new(..)`

→ constructs a new vector using the provided components.

#### Accessing elements

Two types of indexing is available:

Firstly, `usize`

indexing which selects the nth element in the matrix as
viewed in column-major order.

```
let matrix = matrix![
1, 2, 3;
4, 5, 6;
];
assert_eq!(matrix[1], 4);
```

Secondly, `(usize, usize)`

indexing which selects the element at a
particular row and column position.

```
let matrix = matrix![
1, 2, 3;
4, 5, 6;
];
assert_eq!(matrix[(1, 0)], 4);
```

Additionally, component accessors are available for small vectors using commonly recognized names.

```
let mut vector = vector![1, 2, 3, 4, 0, 0];
vector.y = 3;
vector.w = 7;
assert_eq!(vector.x, 1);
assert_eq!(vector.y, 3);
assert_eq!(vector.z, 3);
assert_eq!(vector.w, 7);
assert_eq!(vector.a, 0);
assert_eq!(vector.b, 0);
```

#### Accessing a row or column

You can get a reference to particular row or column using the
`.row()`

or `.column()`

methods.

```
let mut matrix = matrix![
1, 2, 3;
4, 7, 6;
];
let row = matrix.row_mut(1);
row[1] = 5;
assert_eq!(matrix.column(1), &[2, 5]);
```

#### Iteration

Element-wise, column-major order iteration is provided using the following methods.

`.into_iter()`

→ consumes the matrix and returns an owned iterator over each element.`.iter()`

→ returns an iterator over a reference to each element.`.iter_mut()`

→ returns an iterator over a mutable reference to each element.

Iteration over rows and columns is provide using the following methods.

`.iter_rows()`

→ returns an iterator over a reference to each row.`.iter_rows_mut()`

→ returns an iterator over mutable reference to each row.`.iter_columns()`

→ returns an iterator over a reference to each column.`.iter_columns_mut()`

→ returns an iterator over a mutable reference to each column.

#### Slice representation

A slice view of the underlying data is provided using
`.as_slice()`

and
`.as_mut_slice()`

.

```
let mut matrix = matrix![
1, 3, 5;
2, 3, 6;
];
matrix.as_mut_slice()[3] = 4;
assert_eq!(matrix.as_slice(), &[1, 2, 3, 4, 5, 6]);
```

#### Operations

`Matrix`

implements many built-in operators. With scalar operands almost
all operators are implemented and they simply apply the operation to each
element in the matrix. Unary operators will do the equivalent. In the
following example each element in the matrix is multiplied by 2.

```
let matrix = matrix![
1, -3;
3, -7;
];
let expected = matrix![
2, -6;
6, -14;
];
assert_eq!(matrix * 2, expected);
```

`Matrix`

supports addition and subtraction with same size matrices for
element-wise addition and subtraction. In the following example a matrix
is added to itself.

```
let matrix = matrix![
1, -3;
3, -7;
];
let expected = matrix![
2, -6;
6, -14;
];
assert_eq!(matrix + matrix, expected);
```

## Macros

A macro for composing matrices.

A macro for composing row vectors.

A macro for composing vectors.

## Structs

An iterator that moves out of a matrix.

An iterator over columns in a matrix.

A mutable iterator over columns in a matrix.

An iterator over rows in a matrix.

A mutable iterator over rows in a matrix.

Represents a matrix with constant `M`

rows and constant `N`

columns.

## Traits

Defines the absolute value for a type.

A helper trait used for indexing operations.

Defines a multiplicative identity element for a type.

Defines a additive identity element for a type.