Struct nalgebra_sparse::coo::CooMatrix [−][src]
pub struct CooMatrix<T> { /* fields omitted */ }
Expand description
A COO representation of a sparse matrix.
A COO matrix stores entries in coordinate-form, that is triplets (i, j, v)
, where i
and j
correspond to row and column indices of the entry, and v
to the value of the entry.
The format is of limited use for standard matrix operations. Its main purpose is to facilitate
easy construction of other, more efficient matrix formats (such as CSR/COO), and the
conversion between different formats.
Format
For given dimensions nrows
and ncols
, the matrix is represented by three same-length
arrays row_indices
, col_indices
and values
that constitute the coordinate triplets
of the matrix. The indices must be in bounds, but duplicate entries are explicitly allowed.
Upon conversion to other formats, the duplicate entries may be summed together. See the
documentation for the respective conversion functions.
Examples
use nalgebra_sparse::{coo::CooMatrix, csr::CsrMatrix, csc::CscMatrix}; // Initialize a matrix with all zeros (no explicitly stored entries). let mut coo = CooMatrix::new(4, 4); // Or initialize it with a set of triplets coo = CooMatrix::try_from_triplets(4, 4, vec![1, 2], vec![0, 1], vec![3.0, 4.0]).unwrap(); // Push a few triplets coo.push(2, 0, 1.0); coo.push(0, 1, 2.0); // Convert to other matrix formats let csr = CsrMatrix::from(&coo); let csc = CscMatrix::from(&coo);
Implementations
pub fn push_matrix<R: Dim, C: Dim, S: RawStorage<T, R, C>>(
&mut self,
r: usize,
c: usize,
m: &Matrix<T, R, C, S>
)
pub fn push_matrix<R: Dim, C: Dim, S: RawStorage<T, R, C>>(
&mut self,
r: usize,
c: usize,
m: &Matrix<T, R, C, S>
)
Pushes a dense matrix into the sparse one.
This adds the dense matrix m
starting at the r
th row and c
th column
to the matrix.
Panics
Panics if any part of the dense matrix is out of bounds of the sparse matrix
when inserted at (r, c)
.
Construct a zero COO matrix of the given dimensions.
Specifically, the collection of triplets - corresponding to explicitly stored entries - is empty, so that the matrix (implicitly) represented by the COO matrix consists of all zero entries.
Construct a zero COO matrix of the given dimensions.
Specifically, the collection of triplets - corresponding to explicitly stored entries - is empty, so that the matrix (implicitly) represented by the COO matrix consists of all zero entries.
Try to construct a COO matrix from the given dimensions and a collection of (i, j, v) triplets.
Returns an error if either row or column indices contain indices out of bounds, or if the data arrays do not all have the same length. Note that the COO format inherently supports duplicate entries.
An iterator over triplets (i, j, v).
Reserves capacity for COO matrix by at least additional
elements.
This increase the capacities of triplet holding arrays by reserving more space to avoid
frequent reallocations in push
operations.
Panics
Panics if any of the individual allocation of triplet arrays fails.
Example
let mut coo = CooMatrix::new(4, 4); // Reserve capacity in advance coo.reserve(10); coo.push(1, 0, 3.0);
Push a single triplet to the matrix.
This adds the value v
to the i
th row and j
th column in the matrix.
Panics
Panics if i
or j
is out of bounds.
The number of explicitly stored entries in the matrix.
This number includes duplicate entries. For example, if the CooMatrix
contains duplicate
entries, then it may have a different number of non-zeros as reported by nnz()
compared
to its CSR representation.
The row indices of the explicitly stored entries.
The column indices of the explicitly stored entries.
Disassembles the matrix into individual triplet arrays.
Examples
let row_indices = vec![0, 1]; let col_indices = vec![1, 2]; let values = vec![1.0, 2.0]; let coo = CooMatrix::try_from_triplets(2, 3, row_indices, col_indices, values) .unwrap(); let (row_idx, col_idx, val) = coo.disassemble(); assert_eq!(row_idx, vec![0, 1]); assert_eq!(col_idx, vec![1, 2]); assert_eq!(val, vec![1.0, 2.0]);
Trait Implementations
Auto Trait Implementations
impl<T> RefUnwindSafe for CooMatrix<T> where
T: RefUnwindSafe,
impl<T> UnwindSafe for CooMatrix<T> where
T: UnwindSafe,
Blanket Implementations
Mutably borrows from an owned value. Read more
type Output = T
type Output = T
Should always be Self
The inverse inclusion map: attempts to construct self
from the equivalent element of its
superset. Read more
pub fn is_in_subset(&self) -> bool
pub fn is_in_subset(&self) -> bool
Checks if self
is actually part of its subset T
(and can be converted to it).
pub fn to_subset_unchecked(&self) -> SS
pub fn to_subset_unchecked(&self) -> SS
Use with care! Same as self.to_subset
but without any property checks. Always succeeds.
pub fn from_subset(element: &SS) -> SP
pub fn from_subset(element: &SS) -> SP
The inclusion map: converts self
to the equivalent element of its superset.