Struct CsrAdjacencyMatrix 

pub struct CsrAdjacencyMatrix { /* private fields */ }

A matrix in CSR (Compressed Sparse Row) format. The matrix uses a HashMap to map columns to a HashSet of rows. Any matrix entry not contained in a HashSet is assumed to be zero.

use graphrox::matrix::{CsrAdjacencyMatrix, MatrixRepresentation};

let mut matrix = CsrAdjacencyMatrix::new();

matrix.set_entry(1, 0, 0);
matrix.set_entry(1, 1, 2);

assert_eq!(matrix.get_entry(0, 0), 1);
assert_eq!(matrix.get_entry(1, 2), 1);
assert_eq!(matrix.get_entry(2, 2), 0);

Implementations

impl CsrAdjacencyMatrix

pub fn new() -> Self

Creates a new, empty CsrAdjacencyMatrix.

use graphrox::matrix::{CsrAdjacencyMatrix, MatrixRepresentation};

let matrix = CsrAdjacencyMatrix::new();
assert_eq!(matrix.dimension(), 0);
assert_eq!(matrix.entry_count(), 0);

pub fn get_sparse_col_vector(&self, col: u64) -> Vec<u64>

Returns a list of non-zero entries in a column.

use graphrox::matrix::{CsrAdjacencyMatrix, MatrixRepresentation};

let mut matrix = CsrAdjacencyMatrix::new();

matrix.set_entry(1, 5, 2);
matrix.set_entry(1, 5, 10);
matrix.set_entry(1, 5, 11);
matrix.set_entry(1, 9, 5);

let col_vector = matrix.get_sparse_col_vector(5);

assert_eq!(col_vector.len(), 3);
assert!(col_vector.contains(&2));
assert!(col_vector.contains(&10));
assert!(col_vector.contains(&11));

pub fn get_sparse_row_vector(&self, row: u64) -> Vec<u64>

Returns a list of non-zero entries in a row.

Performance

Because the matrix is represented sparsely in memory by a HashMap mapping a column index to a HashSet of row indices, obtaining the sparse row vector requires iterating through all the columns in the matrix and checking whether the row is in the set corresponding to each column. Obtaining the row vector is a much more computationally expensive operation than finding a column vector.

use graphrox::matrix::{CsrAdjacencyMatrix, MatrixRepresentation};

let mut matrix = CsrAdjacencyMatrix::new();

matrix.set_entry(1, 2, 5);
matrix.set_entry(1, 10, 5);
matrix.set_entry(1, 11, 5);
matrix.set_entry(1, 5, 9);

let row_vector = matrix.get_sparse_row_vector(5);

assert_eq!(row_vector.len(), 3);
assert!(row_vector.contains(&2));
assert!(row_vector.contains(&10));
assert!(row_vector.contains(&11));

pub fn col_nonzero_entry_count(&self, col: u64) -> u64

Returns a count of the non-zero entries in a column.

use graphrox::matrix::{CsrAdjacencyMatrix, MatrixRepresentation};

let mut matrix = CsrAdjacencyMatrix::new();

matrix.set_entry(1, 5, 2);
matrix.set_entry(1, 5, 10);
matrix.set_entry(1, 5, 11);
matrix.set_entry(1, 9, 5);

assert_eq!(matrix.col_nonzero_entry_count(5), 3);

pub fn row_nonzero_entry_count(&self, row: u64) -> u64

Returns a count of the non-zero entries in a row.

Performance

Because the matrix is represented sparsely in memory by a HashMap mapping a column index to a HashSet of row indices, counting a row’s entries requires iterating through all the columns in the matrix and checking whether the row is in the set corresponding to each column. Obtaining the entry count in a row is a much more computationally expensive operation than finding the entry count for a column.

use graphrox::matrix::{CsrAdjacencyMatrix, MatrixRepresentation};

let mut matrix = CsrAdjacencyMatrix::new();

matrix.set_entry(1, 2, 5);
matrix.set_entry(1, 10, 5);
matrix.set_entry(1, 11, 5);
matrix.set_entry(1, 5, 9);

assert_eq!(matrix.row_nonzero_entry_count(5), 3);

Trait Implementations

impl Clone for CsrAdjacencyMatrix

fn clone(&self) -> CsrAdjacencyMatrix

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CsrAdjacencyMatrix

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

Formats the value using the given formatter.

impl Default for CsrAdjacencyMatrix

fn default() -> Self

Returns the “default value” for a type.

impl<'a> IntoIterator for &'a CsrAdjacencyMatrix

type Item = (u64, u64)

The type of the elements being iterated over.

type IntoIter = CsrAdjacencyMatrixIter<'a>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl MatrixRepresentation<u8> for CsrAdjacencyMatrix

fn dimension(&self) -> u64

Returns the dimension of the matrix.

fn entry_count(&self) -> u64

Returns the number of non-zero entries in the matrix.

fn get_entry(&self, col: u64, row: u64) -> u8

Returns the value contained at the specified entry in the matrix. If no entry exists, get_entry() will return zero.

fn set_entry(&mut self, entry: u8, col: u64, row: u64)

Adds or overwrites the specified entry in the matrix with the the provided value.

fn zero_entry(&mut self, col: u64, row: u64)

Sets the specified entry in the matrix to zero.

impl ToString for CsrAdjacencyMatrix

fn to_string(&self) -> String

Generates a string representation of a CsrAdjacencyMatrix.

use graphrox::matrix::{CsrAdjacencyMatrix, MatrixRepresentation};

let mut matrix = CsrAdjacencyMatrix::new();

matrix.set_entry(1, 0, 0);
matrix.set_entry(1, 1, 2);
matrix.set_entry(1, 2, 1);
matrix.set_entry(1, 1, 0);

println!("{}", matrix.to_string());

/* Output:

[ 1, 1, 0 ]
[ 0, 0, 1 ]
[ 0, 1, 0 ]

*/