# Trait cgmath::Matrix [−] [src]

```pub trait Matrix: VectorSpace where Self::Scalar: BaseFloat, Self: Index<usize, Output=Self::Column>, Self: IndexMut<usize, Output=Self::Column>, Self: ApproxEq<Epsilon=Self::Scalar> {
type Row: VectorSpace<Scalar=Self::Scalar> + Array<Element=Self::Scalar>;
type Column: VectorSpace<Scalar=Self::Scalar> + Array<Element=Self::Scalar>;
type Transpose: Matrix<Scalar=Self::Scalar, Row=Self::Column, Column=Self::Row>;
fn row(&self, r: usize) -> Self::Row;
fn swap_rows(&mut self, a: usize, b: usize);
fn swap_columns(&mut self, a: usize, b: usize);
fn swap_elements(&mut self, a: (usize, usize), b: (usize, usize));
fn transpose(&self) -> Self::Transpose;

fn as_ptr(&self) -> *const Self::Scalar { ... }
fn as_mut_ptr(&mut self) -> *mut Self::Scalar { ... }
fn replace_col(&mut self, c: usize, src: Self::Column) -> Self::Column { ... }
}```

A column-major matrix of arbitrary dimensions.

Because this is constrained to the `VectorSpace` trait, this means that following operators are required to be implemented:

• `Add<Output = Self>`
• `Sub<Output = Self>`
• `Neg<Output = Self>`

Scalar multiplication:

• `Mul<Self::Scalar, Output = Self>`
• `Div<Self::Scalar, Output = Self>`
• `Rem<Self::Scalar, Output = Self>`

Note that matrix multiplication is not required for implementors of this trait. This is due to the complexities of implementing these operators with Rust's current type system. For the multiplication of square matrices, see `SquareMatrix`.

## Associated Types

### `type Row: VectorSpace<Scalar=Self::Scalar> + Array<Element=Self::Scalar>`

The row vector of the matrix.

### `type Column: VectorSpace<Scalar=Self::Scalar> + Array<Element=Self::Scalar>`

The column vector of the matrix.

### `type Transpose: Matrix<Scalar=Self::Scalar, Row=Self::Column, Column=Self::Row>`

The result of transposing the matrix

## Required Methods

### `fn row(&self, r: usize) -> Self::Row`

Get a row from this matrix by-value.

### `fn swap_rows(&mut self, a: usize, b: usize)`

Swap two rows of this array.

### `fn swap_columns(&mut self, a: usize, b: usize)`

Swap two columns of this array.

### `fn swap_elements(&mut self, a: (usize, usize), b: (usize, usize))`

Swap the values at index `a` and `b`

### `fn transpose(&self) -> Self::Transpose`

Transpose this matrix, returning a new matrix.

## Provided Methods

### `fn as_ptr(&self) -> *const Self::Scalar`

Get the pointer to the first element of the array.

### `fn as_mut_ptr(&mut self) -> *mut Self::Scalar`

Get a mutable pointer to the first element of the array.

### `fn replace_col(&mut self, c: usize, src: Self::Column) -> Self::Column`

Replace a column in the array.

## Implementors

• `impl<S: BaseFloat> Matrix for Matrix2<S>`
• `impl<S: BaseFloat> Matrix for Matrix3<S>`
• `impl<S: BaseFloat> Matrix for Matrix4<S>`