# Unexpected AdjacencyMatrix output [duplicate]

This question already has an answer here:

I have a directed graph with this Edgelist defined as follow:

g = Graph[{1 -> 2, 1 -> 3, 1 -> 4, 1 -> 6, 2 -> 6, 3 -> 8, 3 -> 11, 4 -> 8, 5 -> 2, 5 -> 6, 5 -> 8, 6 -> 8, 6 -> 10, 6 -> 11, 7 -> 2, 7 -> 6, 8 -> 9, 8 -> 11, 9 -> 6, 10 -> 2, 10 -> 9, 11 -> 3,  11 -> 4, 11 -> 9, 11 -> 10}, VertexLabels -> "Name"]


then I want to get the adjacency matrix of this graph by using following:

AdjacencyMatrix[g]//MatrixForm


The first row of that result is:

{0,1,1,1,1,0,0,0,0,0,0}

but it should be:

{0,1,1,1,0,1,0,0,0,0,0}

Can anyone help me to show this adjacency matrix in true form?

## marked as duplicate by Szabolcs, Community♦Aug 16 '15 at 18:42

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

• Vertex names can be anything, not just numbers. When they are consecutive integers, you might assume that they are ordered as 1,2,3,..., but this is not generally true. Make no assumptions about the vertex ordering, instead check it (see VertexList) or use VertexIndex. – Szabolcs Aug 16 '15 at 18:38

## 1 Answer

The problem is that the vertices get numbered by their order of appearance in the graph. This means that what you called vertex "6" is actually considered vertex "5". To see what I mean try the following command:

VertexList[g]


To set the vertices in the desired order, they should be explicitly listed before the edges:

g = Graph[Table[i,{i,1,11}],{1 -> 2, 1 -> 3, 1 -> 4, 1 -> 6, 2 -> 6, 3 -> 8, 3 -> 11, 4 -> 8, 5 -> 2, 5 -> 6, 5 -> 8, 6 -> 8, 6 -> 10, 6 -> 11, 7 -> 2, 7 -> 6, 8 -> 9, 8 -> 11, 9 -> 6, 10 -> 2, 10 -> 9, 11 -> 3,  11 -> 4, 11 -> 9, 11 -> 10}, VertexLabels -> "Name"]