edu.stanford.math.plex

Class Packed2Simplex

java.lang.Object

edu.stanford.math.plex.Simplex

edu.stanford.math.plex.Packed2Simplex

All Implemented Interfaces:

java.lang.Comparable<Simplex>

public class Packed2Simplex
extends Simplex

The Packed2Simplex class implements the abstract class Simplex for Simplices that are points or edges by storing the vertices as 2 packed 32-bit values in a single long int. This limits us to H0 calculations with this representation, but this is the most important case for Mapper use, and increased vertex sizes, and simplicity and speed of this form make it worthwhile.

Version:

$Id$

Field Summary

Fields

Modifier and Type	Field and Description
long	bits
protected static long	DIM_0_MASK
protected static int	MAX_2_INDEX
protected static int	VERTEX_BIT_SZ

Fields inherited from class edu.stanford.math.plex.Simplex

_chain, _findex

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Packed2Simplex()
protected	Packed2Simplex(int v1)
protected	Packed2Simplex(long bits)

Method Summary

Methods

Modifier and Type	Method and Description
protected static void	assert_2_vertices(int[] v)
Simplex[]	boundaryArray() Returns the boundary of self.
protected static boolean	check_2_vertices(int[] v)
protected int	compareTo(Packed2Simplex s)
int	compareTo(Simplex s) Implements Comparable interface.
Simplex	copy() Make a "blank" copy of the Simplex -- equivalent to getSimplex(this.vertices()).
int	dimension() Returns the dimension of self.
boolean	equals(java.lang.Object obj) Overrides Object equals.
int	hashCode() Overrides Object hashcode.
static Simplex	makeEdge(int v1, int v2)
static Simplex	makePoint(int v)
static Simplex	makeSimplex(int[] vertices)
static Simplex	makeSimplexPresorted(int[] vertices)
protected int	v1()
protected int	v2()
int[]	vertices() Returns the indices of self as an array.
int[]	vertices(int[] verts) Returns the indices of self in the given array argument.

Methods inherited from class edu.stanford.math.plex.Simplex

addVertex, addVertex, boundary, chain, clearChain, decrement_findex, dist_sort, findex, getSimplex, getSimplex, getSimplexPresorted, getSimplexPresorted, makeEdge, makePoint, persistence_sort, setChain, setfindex, simplex_reverse_sort, subset, subset, toString, vertex_sort

Methods inherited from class java.lang.Object

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

Field Detail

bits

public final long bits

VERTEX_BIT_SZ

protected static int VERTEX_BIT_SZ

MAX_2_INDEX

protected static int MAX_2_INDEX

DIM_0_MASK

protected static long DIM_0_MASK

Constructor Detail

Packed2Simplex

protected Packed2Simplex()

Packed2Simplex

protected Packed2Simplex(long bits)

Packed2Simplex

protected Packed2Simplex(int v1)

Method Detail

v1

protected int v1()

v2

protected int v2()

check_2_vertices

protected static boolean check_2_vertices(int[] v)

assert_2_vertices

protected static void assert_2_vertices(int[] v)

hashCode

public int hashCode()

Overrides Object hashcode.

Overrides:

hashCode in class Simplex

Returns:

CRC hash of the vertex set.

equals

public boolean equals(java.lang.Object obj)

Overrides Object equals.

Overrides:

equals in class Simplex

Parameters:

obj - object to compare.

Returns:

true or false, depending on whether or not the Simplex is = to obj.

compareTo

protected int compareTo(Packed2Simplex s)

compareTo

public int compareTo(Simplex s)

Implements Comparable interface.

Specified by:

compareTo in interface java.lang.Comparable<Simplex>

Overrides:

compareTo in class Simplex

Parameters:

s - Simplex to compare.

Returns:

negative, 0, or positive, if this <, =, resp. > than s.

copy

public Simplex copy()

Make a "blank" copy of the Simplex -- equivalent to getSimplex(this.vertices()).

Specified by:

copy in class Simplex

Returns:

the copied instance.

dimension

public int dimension()

Returns the dimension of self.

Specified by:

dimension in class Simplex

Returns:

int, the dimension of the simplex.

See Also:

Simplex.dimension()

vertices

public int[] vertices()

Returns the indices of self as an array.

Specified by:

vertices in class Simplex

Returns:

an int[] of vertices, or null if no vertices.

See Also:

Simplex.vertices()

vertices

public int[] vertices(int[] verts)

Returns the indices of self in the given array argument.

Specified by:

vertices in class Simplex

Parameters:

verts - the int[] into which the vertices, if any, are written.

Returns:

the given array argument, or null if no vertices.

See Also:

Simplex.vertices()

makeSimplex

public static Simplex makeSimplex(int[] vertices)

makeSimplexPresorted

public static Simplex makeSimplexPresorted(int[] vertices)

makeEdge

public static Simplex makeEdge(int v1,
               int v2)

makePoint

public static Simplex makePoint(int v)

boundaryArray

public Simplex[] boundaryArray()

Returns the boundary of self.

It is simple enough to do explicitly, and it needs to be fast.

Specified by:

boundaryArray in class Simplex

Returns:

[face0, face1, ...]

See Also:

Simplex.vertices()