# digraph -- Constructs a digraph

## Synopsis

• Usage:
G = digraph E
G = digraph H
G = digraph (V, E)
G = digraph (V, A)
G = digraph A
• Inputs:
• E, a list, Denotes an edge list (a list of ordered pair lists)
• V, a list, Denotes a vertex list
• H, ,
• A, , Denotes an adjacency matrix
• Optional inputs:
• EntryMode (missing documentation) => ..., default value auto,
• Singletons (missing documentation) => ..., default value null,
• Outputs:
• G, an instance of the type Digraph,

## Description

A digraph is a set of vertices connected by directed edges. Unlike the case with simple graphs, {u,v} being an edge does not imply that {v,u} is also an edge. Notably, this allows for non-symmetric adjacency matrices.

 i1 : G = digraph ({{1,2},{2,1},{3,1}}, EntryMode => "edges") o1 = Digraph{1 => {2}} 2 => {1} 3 => {1} o1 : Digraph i2 : G = digraph hashTable{1 => {2}, 3 => {4}, 5 => {6}} o2 = Digraph{1 => {2}} 2 => {} 3 => {4} 4 => {} 5 => {6} 6 => {} o2 : Digraph i3 : G = digraph ({{a,{b,c,d,e}}, {b,{d,e}}, {e,{a}}}, EntryMode => "neighbors") o3 = Digraph{a => {e, b, c, d}} b => {e, d} c => {} d => {} e => {a} o3 : Digraph i4 : G = digraph ({x,y,z}, matrix {{0,1,1},{0,0,1},{0,1,0}}) o4 = Digraph{x => {y, z}} y => {z} z => {y} o4 : Digraph i5 : G = digraph matrix {{0,1,1},{0,0,1},{0,1,0}} o5 = Digraph{0 => {1, 2}} 1 => {2} 2 => {1} o5 : Digraph

• graph -- Constructs a simple graph

## Ways to use digraph :

• "digraph(HashTable)"
• "digraph(List)"
• "digraph(List,List)"
• "digraph(List,Matrix)"
• "digraph(Matrix)"

## For the programmer

The object digraph is .