uk.ac.starlink.array

Class OrderedNDShape

java.lang.Object

uk.ac.starlink.array.NDShape

uk.ac.starlink.array.OrderedNDShape

All Implemented Interfaces:

Cloneable

public class OrderedNDShape
extends NDShape
implements Cloneable

Represents the arrangement of pixels within an N-dimensional array. Instances of this class are NDShapes with an additional ordering specified which indicates the sequence in which pixels are encountered. This class thus defines a mapping between an ordered sequence of positions and their coordinates in N-dimensional space.

Version:

$Id$

Author:

Mark Taylor (Starlink)

Field Summary

Fields inherited from class uk.ac.starlink.array.NDShape

DEFAULT_ORIGIN

Constructor Summary

Constructors

Constructor and Description
OrderedNDShape(long[] origin, long[] dims, Order order) Creates an OrderedNDShape from its origin, dimensions and ordering.
OrderedNDShape(long[] dims, Order order) Creates an OrderedNDShape with a default origin from its dimensions and ordering.
OrderedNDShape(NDShape shape) Creates a new OrderedNDShape from an NDShape.
OrderedNDShape(NDShape shape, Order order) Creates an OrderedNDShape from a NDShape and an ordering.

Method Summary

Modifier and Type	Method and Description
Object	clone()
boolean	equals(Object other) Indicates whether another object is equivalent to this one.
Order	getOrder() Gets the ordering scheme of this object.
int	hashCode()
long[]	offsetToPosition(long offset) Determines the coordinates of a pixel at a given offset within the pixel sequence.
Iterator	pixelIterator() Returns an Iterator which will iterate over all the pixels in this OrderedNDShape's pixel sequence.
Iterator	pixelIterator(long start, long length) Returns an Iterator which will iterate over a range of pixels in this OrderedNDShape's pixel sequence.
long	positionToOffset(long[] pos) Returns the offset of a pixel having given coordinates within the sequence of pixels defined by this OrderedNDShape.
boolean	sameSequence(OrderedNDShape other) Indicates whether another object represents the same pixel sequence as this.
String	toString()

Methods inherited from class uk.ac.starlink.array.NDShape

fromString, getDims, getLimits, getNumDims, getNumPixels, getOrigin, getUpperBounds, intersection, intsToLongs, longsToInts, sameShape, toString, toString, union, within

Methods inherited from class java.lang.Object

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

Constructor Detail

OrderedNDShape

public OrderedNDShape(long[] origin,
                      long[] dims,
                      Order order)

Creates an OrderedNDShape from its origin, dimensions and ordering.

Parameters:

origin - an array representing the origin

dims - an array representing the dimension extents

order - an Order object specifying the pixel ordering scheme. If the null value is supplied, an arbitrary ordering scheme will be applied.

Throws:

IllegalArgumentException - if origin and dims have different lengths or any of the dimensions are not positive

OrderedNDShape

public OrderedNDShape(long[] dims,
                      Order order)

Creates an OrderedNDShape with a default origin from its dimensions and ordering. Each element of the origin array has the value NDShape.DEFAULT_ORIGIN.

Parameters:

dims - an array representing the dimension extents

order - an Order object specifying the pixel ordering scheme. If the null value is supplied, an arbitrary ordering scheme will be applied.

Throws:

IllegalArgumentException - if any of the dimensions are not positive

OrderedNDShape

public OrderedNDShape(NDShape shape,
                      Order order)

Creates an OrderedNDShape from a NDShape and an ordering.

Parameters:

shape - a NDShape object

order - an Order object specifying the pixel ordering scheme If the null value is supplied, an arbitrary ordering scheme will be applied.

OrderedNDShape

public OrderedNDShape(NDShape shape)

Creates a new OrderedNDShape from an NDShape. If shape is in fact an instance of OrderedNDShape, the created object will be equivalent to it. If not, a new OrderedNDShape object will be created with an arbitrary ordering scheme.

Parameters:

shape - an NDShape or OrderedNDShape object

Method Detail

getOrder

public Order getOrder()

Gets the ordering scheme of this object.

Returns:

an Order object indicating the ordering scheme

pixelIterator

public Iterator pixelIterator(long start,
                              long length)

Returns an Iterator which will iterate over a range of pixels in this OrderedNDShape's pixel sequence. The next method of the returned Iterator returns an array of longs giving the coordinates of the next pixel in the sequence. Note that this long array is the same object every time, but its contents change at each iteration. It should not be modified by clients.

Parameters:

start - the first offset in the pixel sequence over which to iterate

length - the number of pixels over which to iterate

Returns:

an Iterator over cells

Throws:

IllegalArgumentException - if start and length would imply iteration outside of this shape or length is negative

pixelIterator

public Iterator pixelIterator()

Returns an Iterator which will iterate over all the pixels in this OrderedNDShape's pixel sequence. The next method of the returned Iterator returns an array of longs giving the coordinates of the next pixel in the sequence. Note that this long array is the same object every time, but its contents change at each iteration. It should not be modified by clients.

Equivalent to pixelIterator(0,getNumPixels());

Returns:

an Iterator over cells

positionToOffset

public long positionToOffset(long[] pos)

Returns the offset of a pixel having given coordinates within the sequence of pixels defined by this OrderedNDShape. It will validate its input, and so may not be maximally efficient.

Parameters:

pos - a coordinate vector giving a pixel position

Returns:

the offset into this shape's pixel sequence at which the pixel at pos occurs

Throws:

IndexOutOfBoundsException - if pos is outside this shape

offsetToPosition

public long[] offsetToPosition(long offset)

Determines the coordinates of a pixel at a given offset within the pixel sequence. It will validate its input, and so may not be maximally efficient.

Parameters:

offset - an offset into the list of pixels

Returns:

the coordinates of the pixel at offset

Throws:

IndexOutOfBoundsException - if offset is outside this shape

clone

public Object clone()

Overrides:

clone in class NDShape

sameSequence

public boolean sameSequence(OrderedNDShape other)

Indicates whether another object represents the same pixel sequence as this. Two shapes are the same if they have the same origins, dimensions and ordering scheme. A true result from this method implies that pixel iterators returned from the two objects will behave in exactly the same way (present the same pixel positions in the same order).

Parameters:

other - the shape to compare with this one

Returns:

true iff the pixel sequences are the same

equals

public boolean equals(Object other)

Indicates whether another object is equivalent to this one.

Overrides:

equals in class NDShape

Parameters:

other - an OrderedNDShape object for comparison with this one

hashCode

public int hashCode()

Overrides:

hashCode in class NDShape

toString

public String toString()

Overrides:

toString in class NDShape