SparseMatrix (JScience v4.3 API)

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org.jscience.mathematics.vector
Class SparseMatrix<F extends Field<F>>

java.lang.Object
  org.jscience.mathematics.vector.Matrix<F>
      org.jscience.mathematics.vector.SparseMatrix<F>

All Implemented Interfaces:: javolution.lang.Immutable, javolution.lang.Realtime, javolution.lang.ValueType, GroupAdditive<Matrix<F>>, Ring<Matrix<F>>, Structure<Matrix<F>>, VectorSpace<Matrix<F>,F>

public final class SparseMatrix<F extends Field<F>>
extends Matrix<F>
extends Matrix<F>

This class represents a matrix made of sparse vectors (as rows). To create a sparse matrix made of column vectors the transpose() method can be used. For example:

        SparseVector<Rational> column0 = SparseVector.valueOf(...);
        SparseVector<Rational> column1 = SparseVector.valueOf(...);
        SparseMatrix<Rational> M = SparseMatrix.valueOf(column0, column1).transpose();

As for any concrete structure, this class is declared final (otherwise most operations would have to be overridden to return the appropriate type). Specialized dense matrix should sub-class Matrix directly. For example:

        // Extension through composition.
        final class BandMatrix <F extends Field<F>> extends Matrix<F> {
             private SparseMatrix<F> _value;
             ...
             public BandMatrix opposite() { // Returns the right type.
                 return BandMatrix.valueOf(_value.opposite());
             }
             ...
        }

Version:: 3.3, January 2, 2007
Author:: Jean-Marie Dautelle

Field Summary

Fields inherited from class org.jscience.mathematics.vector.Matrix
`XML`

Method Summary

SparseMatrix<F> adjoint()
Returns the adjoint of this matrix.

F cofactor(int i, int j)
Returns the cofactor of an element in this matrix.

SparseMatrix<F> copy()
Returns a copy of this matrix allocated by the calling thread (possibly on the stack).

F determinant()
Returns the determinant of this matrix.

F get(int i, int j)
Returns a single element from this matrix.

SparseVector<F> getColumn(int j)
Returns the column identified by the specified index in this matrix.

SparseVector<F> getDiagonal()
Returns the diagonal vector.

int getNumberOfColumns()
Returns the number of columns n for this matrix.

int getNumberOfRows()
Returns the number of rows m for this matrix.

SparseVector<F> getRow(int i)
Returns the row identified by the specified index in this matrix.

F getZero()
Returns the value of the non-set elements for this sparse matrix.

SparseMatrix<F> inverse()
Returns the inverse of this matrix (must be square).

SparseMatrix<F> minus(Matrix<F> that)
Returns the difference between this matrix and the one specified.

SparseMatrix<F> opposite()
Returns the negation of this matrix.

SparseMatrix<F> plus(Matrix<F> that)
Returns the sum of this matrix with the one specified.

Matrix<F> solve(Matrix<F> y)
Solves this matrix for the specified matrix (returns x such as this · x = y).

SparseMatrix<F> tensor(Matrix<F> that)
Returns the linear algebraic matrix tensor product of this matrix and another (Kronecker product).

SparseMatrix<F> times(F k)
Returns the product of this matrix by the specified factor.

SparseMatrix<F> times(Matrix<F> that)
Returns the product of this matrix with the one specified.

SparseVector<F> times(Vector<F> v)
Returns the product of this matrix by the specified vector.

SparseMatrix<F> transpose()
Returns the transpose of this matrix.

static



<F extends Field<F>> 


SparseMatrix<F>

valueOf(java.util.List<SparseVector<F>> rows)
Returns a sparse matrix holding the row vectors from the specified collection (column vectors if transposed).

static



<F extends Field<F>> 


SparseMatrix<F>

valueOf(Matrix<F> that,
        F zero)

Returns a sparse matrix equivalent to the specified matrix but with the zero elements removed using the default object equality comparator.

static



<F extends Field<F>> 


SparseMatrix<F>

valueOf(Matrix<F> that,
        F zero,
        javolution.util.FastComparator<? super F> comparator)

Returns a sparse matrix equivalent to the specified matrix but with the zero elements removed using the specified object equality comparator.

static



<F extends Field<F>> 


SparseMatrix<F>

valueOf(SparseVector<F>... rows)
Returns a sparse matrix holding the specified row vectors (column vectors if transposed).

static



<F extends Field<F>> 


SparseMatrix<F>

valueOf(Vector<F> diagonal,
        F zero)

Returns the sparse square matrix having the specified diagonal vector.

SparseVector<F> vectorization()
Returns the vectorization of this matrix.

Methods inherited from class org.jscience.mathematics.vector.Matrix
`divide, equals, equals, hashCode, isSquare, pow, pseudoInverse, solve, toString, toText, trace`

Methods inherited from class java.lang.Object
`clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

Method Detail

valueOf

public static <F extends Field<F>> SparseMatrix<F> valueOf(Vector<F> diagonal,
                                                           F zero)

Returns the sparse square matrix having the specified diagonal vector. This method is typically used to create an identity matrix. For example:

      SparseMatrix<Real> IDENTITY = Matrix.valueOf(
           DenseVector.valueOf({Real.ONE, Real.ONE, Real.ONE}), Real.ZERO);

Parameters:: diagonal - the diagonal vector.; zero - value of non-diagonal elements.
Returns:: a square matrix with diagonal on the diagonal and zero elsewhere.

valueOf

public static <F extends Field<F>> SparseMatrix<F> valueOf(SparseVector<F>... rows)

Returns a sparse matrix holding the specified row vectors (column vectors if transposed).

Parameters:: rows - the row vectors.
Returns:: the matrix having the specified rows.
Throws:: DimensionException - if the rows do not have the same dimension.

valueOf

public static <F extends Field<F>> SparseMatrix<F> valueOf(java.util.List<SparseVector<F>> rows)

Returns a sparse matrix holding the row vectors from the specified collection (column vectors if transposed).

Parameters:: rows - the list of row vectors.
Returns:: the matrix having the specified rows.
Throws:: DimensionException - if the rows do not have the same dimension.

valueOf

public static <F extends Field<F>> SparseMatrix<F> valueOf(Matrix<F> that,
                                                           F zero)

Returns a sparse matrix equivalent to the specified matrix but with the zero elements removed using the default object equality comparator.

Parameters:: that - the matrix to convert.; zero - the zero element for the sparse vector to return.
Returns:: SparseMatrix.valueOf(that, zero, FastComparator.DEFAULT) or a dense matrix holding the same elements

valueOf

public static <F extends Field<F>> SparseMatrix<F> valueOf(Matrix<F> that,
                                                           F zero,
                                                           javolution.util.FastComparator<? super F> comparator)

Returns a sparse matrix equivalent to the specified matrix but with the zero elements removed using the specified object equality comparator.

Parameters:: that - the matrix to convert.; zero - the zero element for the sparse vector to return.; comparator - the comparator used to determinate zero equality.
Returns:: that or a dense matrix holding the same elements as the specified matrix.

getZero

public F getZero()

Returns the value of the non-set elements for this sparse matrix.

Returns:: the element corresponding to zero.