Index library#

To use one of the described component here, you have to import them from revsymg.index_lib.

Types#

Type	Alias - value	Description
`IndexT`	`int`	Index type
`OrT`	\(\mathbb{B} = \{0 ; 1\}\)	Orientations type
`IndOrT`	`tuple` (`IndexT`, `OrT`)	Oriented vertex type
`EIndOrT`	`tuple` (`IndOrT`, `IndOrT`)	Edges type
`IndOrIndT`	`tuple` (`IndOrT`, `IndexT`)	Adjacent vertex with edge index type
`EIndOrIndT`	`tuple` (`EIndOrT`, `IndexT`)	Edges with edge index type

IndexT#: Index type

OrT#

Orientations type

Value:: binaries set \(\mathbb{B} = \{0 ; 1\}\)

IndOrT#

Oriented vertex type

Value:: tuple (IndexT, OrT)

EIndOrT#

Edges type.

Value:: tuple (IndOrT, IndOrT)

IndOrIndT#

Adjacent vertex with edge index type.

Value:: tuple (IndOrT, IndexT)

EIndOrIndT#

Edges with edge index type.

Value:: tuple (EIndOrT, IndexT)

Constants#

For OrT type:

`FORWARD_INT`	Forward orientation value.
`REVERSE_INT`	Reverse orientation value.
`ORIENT_REV`	`OrT` reverse list.
`FWDOR_REVOR`	`OrT` relative orientation.

For IndOrT type:

`IND`	The index for `IndOrT`'s index value.
`OR`	The index for `IndOrT`'s orientation value.

For EIndOrT type:

`PRED_IND`	The index for predecessors of forwards in adjancies table
`SUCC_IND`	The index for successors of forwards in adjancies table

For IndOrIndT type:

`ADJ_INDOR`	The index for `IndOrT` value in `IndOrIndT`.
`ADJ_IND`	The index for `IndexT` value in `IndOrIndT`.

For EIndOrIndT type:

E_IND

The index of edge's index in the edge.

Other:

MULT_IID

Index multiplier.

All the constants

FORWARD_INT = 0#

Forward orientation value.

type: OrT

REVERSE_INT = 1#

Reverse orientation value.

type: OrT

ORIENT_REV = (1, 0)#

OrT reverse list.

type: tuple (OrT, OrT)

FWDOR_REVOR = ((0, 1), (1, 0))#

OrT relative orientation.

type: tuple ((OrT, OrT), (OrT, OrT))

IND = 0#: The index for IndOrT’s index value.

OR = 1#: The index for IndOrT’s orientation value.

PRED_IND = 0#: The index for predecessors of forwards in adjancies table

SUCC_IND = 1#: The index for successors of forwards in adjancies table

ADJ_INDOR = 0#: The index for IndOrT value in IndOrIndT.

ADJ_IND = 1#: The index for IndexT value in IndOrIndT.

E_IND = 2#

The index of edge’s index in the edge.

For both EIndOrIndT and EIndIndT it corresponds to IndexT value.

MULT_IID = 2#: Index multiplier.

Functions#

For IndOrT type:

`is_forward`(vertex)	Return True if the vertex is considered as forward.
`is_reverse`(vertex)	Return True if the vertex is considered as reverse.
`rev_vertex`(vertex)	Return the reverse vertex.

For EIndOrT type:

`rev_edge`(first_vertex, second_vertex)	Return the reverse edge.
`is_canonical`(first_vertex, second_vertex)	Xor boolean function between edge and its reverse.
`eindor_orientation`(first_vertex, second_vertex)	Return the edge orientation.

All the functions:

is_forward(vertex)#

Return True if the vertex is considered as forward.

Parameters:: vertex (IndOrT) – A vertex
Returns:: True if vertex’s orientation is forward
Return type:: bool

is_reverse(vertex)#

Return True if the vertex is considered as reverse.

Parameters:: vertex (IndOrT) – Oriented vertex
Returns:: True is vertex is in reverse orientation
Return type:: bool

rev_vertex(vertex)#

Return the reverse vertex.

Parameters:: vertex (IndOrT) – Oriented vertex
Returns:: The reversed of vertex
Return type:: IndOrT

rev_edge(first_vertex, second_vertex)#

Return the reverse edge.

Parameters:

first_vertex (IndOrT) – First oriented vertex in the edge
second_vertex (IndOrT) – Second oriented vertex in the edge

Returns:

The reversed of edge

Return type:

EIndOrT

is_canonical(first_vertex, second_vertex)#

Xor boolean function between edge and its reverse.

Parameters:

first_vertex (IndOrT) – First oriented vertex in the edge
second_vertex (IndOrT) – Second oriented vertex in the edge

Returns:

True if \(\texttt{is_canonical}(\overline{edge})\) is False, else False

Return type:

bool

Notes

\(\texttt{is_canonical}\) is defined such as \(\texttt{is_canonical}(edge) \veebar \texttt{is_canonical}(\overline{edge})\)

eindor_orientation(first_vertex, second_vertex)#

Return the edge orientation.

Parameters:

first_vertex (IndOrT) – First oriented vertex in the edge
second_vertex (IndOrT) – Second oriented vertex in the edge

Returns:

Edge orientation

Return type:

OrT

Notes

This is pure definition. Note that in case of self loop, return value is FORWARD_INT