com.numericalmethod.suanshu.matrix.generic.matrixtype
Class RealMatrix

java.lang.Object
  com.numericalmethod.suanshu.matrix.generic.matrixtype.RealMatrix

All Implemented Interfaces:

AbelianGroup<RealMatrix>, Monoid<RealMatrix>, Ring<RealMatrix>, VectorSpace<RealMatrix,Real>, Matrix<RealMatrix,Real>, MatrixAccessor<Real>, MatrixDimension

public class RealMatrix
extends java.lang.Object
implements Matrix<RealMatrix,Real>

This class represents a matrix of Real numbers.

Comparing to the double-based DenseMatrix, this class allows arbitrary precision arithmetic at the cost of (much) slower performance.

For some high precision mathematics, we often do the calculation using more number of decimal points. We then cast back the results to double for higher accuracy.

Constructor Summary

RealMatrix(double[][] data)
Construct a RealMatrix from a 2D array of doubles.

RealMatrix(int nRows, int nCols)
Construct a nRows x nCols matrix of Real numbers.

RealMatrix(Real[][] data)
Construct a matrix from a 2D array of Real numbers.

Method Summary

RealMatrix	add(RealMatrix that) + : G × G → G
DenseMatrix	doubleValue() Create a DenseMatrix of double values from this real matrix.
boolean	equals(java.lang.Object obj)
Real	get(int row, int col) Get the matrix element at [row, col].
int	hashCode()
RealMatrix	minus(RealMatrix that) - : G × G → G - is not in the definition of of an additive group but can be deduced.
RealMatrix	multiply(RealMatrix that) · : G × G → G
int	nCols() Get the number of columns.
int	nRows() Get the number of rows.
RealMatrix	ONE() The multiplicative element 1 in the group such that for any elements a in the group, the equation 1 × a = a × 1 = a holds.
RealMatrix	opposite() For each a in G, there exists an element b in G such that a + b = b + a = 0 That is, it is the object such as this.add(this.opposite()) == this.ZERO
RealMatrix	scaled(Real scalar) * : F × V → V The result of applying this function to scalar, c, in F and v in V is denoted cv.
void	set(int row, int col, Real value) Set the matrix element at [row, col] to value.
java.lang.String	toString()
RealMatrix	ZERO() The additive element 0 in the group, such that for all elements a in the group, the equation 0 + a = a + 0 = a holds.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

RealMatrix

public RealMatrix(int nRows,
                  int nCols)

Construct a nRows x nCols matrix of Real numbers.

Parameters:

nRows - number of rows

nCols - number of columns

RealMatrix

public RealMatrix(Real[][] data)

Construct a matrix from a 2D array of Real numbers.

Parameters:

data - a matrix arrangement of Real numbers in a 2D array

RealMatrix

public RealMatrix(double[][] data)

Construct a RealMatrix from a 2D array of doubles.

Parameters:

data - a matrix arrangement of doubles in a 2D array

Method Detail

nRows

public int nRows()

Description copied from interface: MatrixDimension

Get the number of rows. Rows count from 1.

Specified by:

nRows in interface MatrixDimension

Returns:

the number of rows

nCols

public int nCols()

Description copied from interface: MatrixDimension

Get the number of columns. Columns count from 1.

Specified by:

nCols in interface MatrixDimension

Returns:

the number of columns

set

public void set(int row,
                int col,
                Real value)

Description copied from interface: MatrixAccessor

Set the matrix element at [row, col] to value.

This is the only function that may change the entries of a matrix.

Specified by:

set in interface MatrixAccessor<Real>

Parameters:

row - the row index

col - the column index

value - the value to set A[row, col] to

get

public Real get(int row,
                int col)

Description copied from interface: MatrixAccessor

Get the matrix element at [row, col].

Specified by:

get in interface MatrixAccessor<Real>

Parameters:

row - the row index

col - the column index

Returns:

A[row, col]

add

public RealMatrix add(RealMatrix that)

Description copied from interface: AbelianGroup

+ : G × G → G

Specified by:

add in interface AbelianGroup<RealMatrix>

Parameters:

that - the object to be added

Returns:

this + that

minus

public RealMatrix minus(RealMatrix that)

Description copied from interface: AbelianGroup

- : G × G → G

- is not in the definition of of an additive group but can be deduced. This function is provided for convenience purpose. It is equivalent to

this.add(that.opposite())

Specified by:

minus in interface AbelianGroup<RealMatrix>

Parameters:

that - the object to be subtracted (subtrahend)

Returns:

this - that

multiply

public RealMatrix multiply(RealMatrix that)

Description copied from interface: Monoid

· : G × G → G

Specified by:

multiply in interface Monoid<RealMatrix>

Parameters:

that - the multiplicand

Returns:

this × that

scaled

public RealMatrix scaled(Real scalar)

Description copied from interface: VectorSpace

* : F × V → V

The result of applying this function to scalar, c, in F and v in V is denoted cv.

Specified by:

scaled in interface VectorSpace<RealMatrix,Real>

Parameters:

scalar - a multiplier

Returns:

scalar * this

See Also:

Wikipedia: Scalar multiplication

opposite

public RealMatrix opposite()

Description copied from interface: AbelianGroup

For each a in G, there exists an element b in G such that

a + b = b + a = 0

That is, it is the object such as

this.add(this.opposite()) == this.ZERO

Specified by:

opposite in interface AbelianGroup<RealMatrix>

Returns:

-this

See Also:

Wikipedia: Additive inverse

ZERO

public RealMatrix ZERO()

Description copied from interface: AbelianGroup

The additive element 0 in the group, such that for all elements a in the group, the equation

0 + a = a + 0 = a

holds.

Specified by:

ZERO in interface AbelianGroup<RealMatrix>

Returns:

0

ONE

public RealMatrix ONE()

Description copied from interface: Monoid

The multiplicative element 1 in the group such that for any elements a in the group, the equation

1 × a = a × 1 = a

holds.

Specified by:

ONE in interface Monoid<RealMatrix>

Returns:

1

doubleValue

public DenseMatrix doubleValue()

Create a DenseMatrix of double values from this real matrix.

Returns:

a double matrix of type DenseMatrix

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object