How to identify or select some nodes in a graph

Mar 19, 2010 at 8:56 PM

Hi - I've been using NodeXL to analyze the relationships among about 4,000 mainframe programs that call each other. I was trying to get some sort of picture of the program dependencies, and NodeXL created a nice graph. The graph shows 3 concentric rings, and now I'd like to identify the vertices that make up each ring, but I can't figure out how to do that. Is there some way to select the inner or middle ring of vertices? Or is there some data element in the spreadsheet that I can use for sorting? 

Here's an image of the graph that was produced. 

I know this tool was intended to visualize social networks, but it works well for really old school stuff like mainframe programs, too.


Mar 19, 2010 at 10:44 PM
Edited Mar 19, 2010 at 10:51 PM

I'll assume that you are using version 113 or earlier of NodeXL.  You can tell which version you have by going to NodeXL, Help, About Microsoft NodeXL in Excel's ribbon.  (The technique for selecting vertices changed and became more obvious in later versions.)

To select the vertices in a ring, do the following:

1. While holding down the left mouse button, drag a box around the ring.  That selects all the vertices in the box.

2. While holding down the left mouse button and the Alt key, drag a box around any vertices in the ring's interior that you don't want selected.  If there are stray vertices that are still selected but shouldn't be (or vice versa), click each such vertex while holding down the Ctrl key.

If you forget how to do this, click About Zoom and Scale at the top of the graph pane.

Once you have the vertices in your ring selected, you can "mark" them in the workbook to identify them:

3. Right-click the graph pane and select Edit Selected Vertex Properties.

4. In the Vertex Properties dialog box, set Marked? to Yes, then click OK.  This adds a Marked? column to the Vertices worksheet.

5. Click the down-arrow at the top of the Marked? column on the Vertices worksheet, then select Sort Z to A.  The marked vertices, which are the vertices in your selected ring, will move to the top of the worksheet.

I'm glad to hear of your "off-label" use of our program!  FDA approval not required.

-- Tony