com.numericalmethod.suanshu.matrix.doubles.matrixtype.sparse
Interface SparseMatrix

All Superinterfaces:

AbelianGroup<Matrix>, DeepCopyable, Densifiable, Matrix, MatrixAccess, MatrixRing, MatrixTable, Monoid<Matrix>, Ring<Matrix>, SparseStructure, Table

All Known Implementing Classes:

CSRSparseMatrix, DOKSparseMatrix, LILSparseMatrix

public interface SparseMatrix
extends Matrix, Densifiable, SparseStructure

A sparse matrix stores only non-zero values. When there are only a few non-zeros in a matrix, sparse matrix saves memory space for storing the matrix. In addition, the matrix operations based on sparse matrix are usually more efficient. The time complexities are proportional to the number of non-zero values instead of the dimension-squared of dense matrix.

See Also:

Wikipedia: Sparse matrix

Method Summary

java.util.List<SparseEntry>

getEntrytList() Export the non-zero values in the matrix as a list of SparseEntrys.

Methods inherited from interface com.numericalmethod.suanshu.matrix.doubles.Matrix

deepCopy, getColumn, getRow, multiply, scaled

Methods inherited from interface com.numericalmethod.suanshu.matrix.doubles.MatrixAccess

get, set

Methods inherited from interface com.numericalmethod.suanshu.datastructure.Table

nCols, nRows

Methods inherited from interface com.numericalmethod.suanshu.matrix.doubles.MatrixRing

add, minus, multiply, ONE, opposite, t, ZERO

Methods inherited from interface com.numericalmethod.suanshu.matrix.doubles.matrixtype.dense.Densifiable

toDense

Methods inherited from interface com.numericalmethod.suanshu.matrix.doubles.matrixtype.sparse.SparseStructure

nNonZeros

Method Detail

getEntrytList

java.util.List<SparseEntry> getEntrytList()

Export the non-zero values in the matrix as a list of SparseEntrys. This is useful for converting between the different formats of SparseMatrix. For example,

 // construct matrix using DOK
 DOKSparseMatrix dok = new DOKSparseMatrix(5, 5);
 // ... insert some values to DOK matrix
 // convert to CSR matrix for efficient matrix operations
 CSRSparseMatrix csr = new CSRSparseMatrix(5, 5, dok.getEntrytList());
 

Returns:

the sparse entries