org.jutil.math.matrix
Class NMatrix

java.lang.Object
  |
  +--org.jutil.math.matrix.NMatrix

Direct Known Subclasses:

Matrix

public abstract class NMatrix

extends java.lang.Object

This is a class of N-dimensional matrices The name Matrix has been reserved for 2D matrices since they are use more frequently than a general N-dimensional matrix. Since java has no generic classes, a matrix contains double values.

Class Specifications

public invariant getDimensions().length == getNbDimensions(); public invariant ( \forall int i; i >= 0&&i < getNbDimensions(); getDimensions()[i] > 0);

Field Summary
static java.lang.String	CVS_REVISION

 

Constructor Summary

NMatrix()

 

Method Summary
abstract  double	elementAt(int[] index)           Return the element at the given index.
abstract  int[]	getDimensions()           Return the dimensions of this matrix
abstract  int	getNbDimensions()           Return the number of dimensions of this matrix.
abstract  void	setElementAt(int[] index, double value)           Set the element at the given index to the given value.
boolean	validIndex(int[] index)           Check whether or not the given index is a valid index for this matrix.

 

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

 

Field Detail

CVS_REVISION

public static final java.lang.String CVS_REVISION

NMatrix

public NMatrix()

getNbDimensions

public abstract int getNbDimensions()

Return the number of dimensions of this matrix.

getDimensions

public abstract int[] getDimensions()

Return the dimensions of this matrix

Specifications:

ensures \result .length == getNbDimensions();

elementAt

public abstract double elementAt(int[] index)

Return the element at the given index.

Parameters:

index - The index of the requested element.

Specifications:

requires validIndex(index);

setElementAt

public abstract void setElementAt(int[] index,
                                  double value)

Set the element at the given index to the given value.

Parameters:

index - The index of the element to be changed.

value - The new value for the element at index .

Specifications:

requires validIndex(index);
ensures elementAt(index) == value;

validIndex

public boolean validIndex(int[] index)

Check whether or not the given index is a valid index for this matrix.

Parameters:

index - The index to be verified.

Specifications:

ensures \result == (index != null)&&(index.length == getNbDimensions())&&( \forall int i; i >= 0&&i < getNbDimensions(); (index[i] > 0)&&(index[i] <= getDimensions()[i]));