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

All Superinterfaces:

AbelianGroup<Matrix>, DeepCopyable, Densifiable, Matrix, MatrixAccessor, MatrixDimension, MatrixRing, Monoid<Matrix>, Ring<Matrix>, SparseStructure

All Known Implementing Classes:

CsrSparseMatrix, DokSparseMatrix, LilSparseMatrix

public interface SparseMatrix
extends Matrix, Densifiable, SparseStructure

This interface defines the sparse matrix which stores non-zero values only. If there are only a few non-zeros in a matrix, sparse matrix does save memory space for storing the matrix. In addition, matrix operations based on sparse matrix are also more efficient. Usually, the time complexities of are just proportional to the number of non-zero values, instead of the dimension of the matrix as in the dense case.

Method Summary

java.util.List<SparseElement>

toElementList() Export the non-zero values in the matrix as a list of SparseElements.

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

deepCopy, multiply, scaled

Methods inherited from interface com.numericalmethod.suanshu.matrix.MatrixDimension

nCols, nRows

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

get, getColumn, getRow, set

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

dropTolerance, nnz

Method Detail

toElementList

java.util.List<SparseElement> toElementList()

Export the non-zero values in the matrix as a list of SparseElements.

This is useful for converting between SparseMatrix of different formats. 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.toElementList());
 

Returns:

the element list