Struct aph::Triangular

pub struct Triangular<F> { /* private fields */ }

Triangular matrix representation.

As the Markov chain underlying an APH distribution has no cycles, its infinitesimal generator matrix has the form

$$ \begin{pmatrix} d(1) & \lambda_{1,2} & \cdots & \lambda_{1,N} & \lambda_{1,N+1} \\ 0 & d(2) & \cdots & \lambda_{2,N} & \lambda_{2,N+1} \\ \vdots & \vdots & \ddots & \vdots & \vdots \\ 0 & 0 & \cdots & d(N) & \lambda_{N,N+1} \\ 0 & 0 & \cdots & 0 & 0 \end{pmatrix} $$

where the diagonal is given by:

$$ d(i) := -\sum_{k=i + 1}^{N} \lambda_{i,k} $$

To store the matrix, it thus suffices to store the values for all $\lambda_{i,j}$ with $1 \leq i < j \leq N + 1$.

⚠️ Rows and columns are 0-indexed in the implementation.

Implementations

impl<F: PseudoField> Triangular<F>

pub fn new(size: usize) -> Self

Creates a new triangular representation of the given size.

pub fn set(
    &mut self,
    row: usize,
    column: usize,
    value: impl Into<F>
) -> &mut Self

Sets the value at the given row and column.

Panics

Panics if column is not greater than row or if the access is out-of-bounds.

pub fn get(&self, row: usize, column: usize) -> F

Returns the value at the given row and column.

Panics

Panics if the access is out-of-bounds.

pub fn diagonal(&self, row: usize) -> F

Computes the value of the diagonal of the given row.

Panics

Panics if the access is out-of-bounds

Trait Implementations

impl<F: Clone> Clone for Triangular<F>

fn clone(&self) -> Triangular<F>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<F: Debug> Debug for Triangular<F>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<F: PseudoField> Representation<F> for Triangular<F>

fn size(&self) -> usize

The size $N$ of the APH representation.

fn get(&self, row: usize, column: usize) -> F

Returns the value at the given row and column.

fn diagonal(&self, row: usize) -> F

Returns the value at the diagonal of the given row.

fn dimension(&self) -> usize

The dimension of the generator matrix.