Edges and Vertices question

Nov 3, 2008 at 11:11 PM
Hello colleagues,

I have Supreme Court cases and what states filed amici briefs for each, I am trying to find the relationship between states, what influences one state to sign the brief with another while other do not. Part of my analysis I am doing in .NetMap. My question is; .NetMap has and edges tab and a vertices tab, I am not sure what should be the edges and what should be the vertices. I can create an incidence matrix in excel, but do not know how to put that into .NetMap.

Thank you in advance for any help you may be able to give.



Maureen Mohan
Graduate Student
Southern Illinois University
Department of Political Science

Nov 4, 2008 at 12:11 AM

Please hover your mouse over the "Edges Worksheet Overview" and "Vertices Worksheet Overview" cells in the Edges and Vertices worksheets for a quick overview.  You may have to scroll horizontally to see those cells, depending on how large your screen is.

Basically, you enter your relationships in a two-column format on the Edges worksheet, and you can probably ignore the Vertices worksheet entirely.  Let's say that you've found that Illinois is related to Nebraska, and Florida is related to Oregon, and Oregon is related to Illinois.  You would fill in the first two columns of the Edges worksheet like so (sorry, the columns won't line up here):

Vertex 1  Vertex 2 
Illinois    Nebraska
Florida    Oregon
Oregon    Illinois

You then click "Read Workbook" in the graph pane on the right side of the worksheet, and you'll get a graph with four vertices connected by three edges.

You would use the Vertices worksheet for two reasons: 1) to customize the appearance of your vertices; or 2) to add isolated vertices not connected to any edges.  In the latter case, you would have to set the Visibility column to "Show" to get the isolated vertices to show up in the graph.  If neither reason applies to you, ignore the Vertices worksheet.

We do not yet have a way to automatically convert a matrix representation of a graph to an edge list, although that is on our feature request list.

Let us know if you have additional questions.

-- Tony