Calculations with Multiple Edges between Two Nodes

Oct 19, 2011 at 5:36 AM
Edited Oct 19, 2011 at 5:37 AM

I'm interested in learning more about how I can either draw and/or do calculations with multiple edges between just two nodes.  I've already read a similar discussion on the topic of multiple edges here:

Here's what I'm working on.  I'm drawing a graph where one node/vertex represents a person and the second node/vertex represents a location.  The edge is a numerical transaction.  The person may conduct "x" number of transactions for varying amounts at any given location.  I understand that currently I will be unable to graphically represent all these edges between the two nodes, but I'm curious as to whether I can have NodeXL add the amounts for each edge and then represent the sum total on the edge label.

Example:  John makes 7 separate purchases at Best Buy for a total of $800.  Each purchase would be it's own edge between the nodes of John and Best Buy.  How can I get NodeXL to run the calculation and display the sum total on the graph edge label?  Also, I should note, I'd prefer to keep the transactions as separate edges, if possible.

Is this possible?  Any suggestions?

Thanks in advance for the help.

Oct 19, 2011 at 4:12 PM

Are you a programmer using the NodeXL class libraries to create your own graph application, or are you using the NodeXL Excel template?

-- Tony

Oct 19, 2011 at 7:58 PM

I'm using the NodeXL Excel template.  I have zero programming skills and/or knowledge.

Oct 19, 2011 at 8:27 PM

In that case, I don't know how to do what you want to do while keeping the transactions as separate edges.

However, if you are willing to combine the transactions, at least temporarily, I think the following steps will give you what you want:

1. Select NodeXL, Data, Prepare Data, Merge Duplicate Edges.  This merges the transactions and adds an Edge Weight column to the Edges worksheet.

2. Select NodeXL, Visual Properties, Autofill Columns.

3. In the Autofill Columns dialog box, select Edge Weight for Edge Label and click Autofill.  This adds a numerical label to each merged edge that is the number of transactions the edge represents.

If you are just after an image with edge labels, keep in mind that you can perform these steps, save an image of the merged, labeled graph (right-click the graph pane and select Save Image to File), and then discard your changes by closing the workbook without saving it.  That way you won’t lose your separate transactions.

-- Tony


Oct 19, 2011 at 8:45 PM

Thanks.  I appreciate the response.

Can you maybe recommend another program that would accomplish what I'm trying to do?  I mentioned in another post that I tried out Gephi, but I have a lot to learn.  I am very, very new to this field.

NodeXL is great because I was able to build a lot of great graphs with just my basic knowledge of Excel and some help from the Analyzing Social Media Networks with NodeXL book.  Gephi (and other programs I've found) speak a language I am completely unfamiliar with.

I am, however, willing to learn.  So, if you can recommend something, I'd certainly appreciate it.

Oct 19, 2011 at 10:00 PM

I'm not familiar enough with the other graphing applications to be able to help you here, but perhaps other readers have some suggestions.

-- Tony