How to import multi graphml files into Nodexl?

Feb 26, 2011 at 10:22 AM

I am trying to analyze four of my friends' social network. So I generate 4 GraphML files using namegen web Facebook API. Then I try to import this 4 GraphML files in NodeXL using the function key "From GraphML files". I have grouped these 4 files into a folder and select this folder in order to import all the files into NodeXL. But it pops up a windows showing the message "Done. GraphML files imported: 0." As a result, I cannot import any file in the NodeXL. So I want to ask how I can import those files into NodeXL. Thank you. 

Feb 26, 2011 at 5:16 PM

Dennis:

The Import from GraphML Files feature looks for files with a ".graphml" extension.  If your files have any other extension, the feature will not find them.

Please note that a related feature lets you import an individual GraphML file into the current NodeXL workbook.  It's at NodeXL, Data, Import, From GraphML File (note that lack of an "s" at the end), and unlike the multiple-file feature, it lets you specify a file with an ".xml" extension.

-- Tony

Feb 28, 2011 at 1:20 AM

Thanks for your reply, but I have tried importing each file individually using the function key "From GraphML File". Then the NodeXL is able to recognize those file and can be genrate a network graph. When I import those file using the function key "From GraphML files", all the files are grouped in the folder. Since this folder is only contain the 4 GraphML files withount any other file extension.

Feb 28, 2011 at 4:59 AM

Dennis:

Can you post a list of the file names that aren't working?  I'm wondering if there is something different about them that is causing NodeXL to not recognize them.

In Windows Explorer, you can shift-right-click a file and select Copy as Path to copy the exact name of each file, including the path.  I need the exact paths; please don't type them.

Thanks,
    Tony

Feb 28, 2011 at 6:03 AM

Thnaks for your reply. After checking the file extension, I have modified the file extension from  ".xml" to ".graphml". Now, I am able to import those files. It generate the other 4 files with the extension ".xlsx". But the problem is, can I merge all the friends in this 4 GraphML files into one files. So that I can analyze the full friend's network in a single NodeXL interface? Thanks.

Feb 28, 2011 at 4:23 PM

Dennis:

What is in the GraphML files?  If they contain only edges, edge attributes, and vertices (but NOT vertex attributes), then there are at least three ways to merge multiple sets of data in NodeXL.  In your case, I think the easiest is as follows:

1. Forget about the Import from GraphML Files feature.

2. Start with an empty NodeXL workbook.

3. In the Excel Ribbon, uncheck NodeXL, Data, Import, Clear NodeXL Workbook First.

4. Use Import from GraphML File to import your first GraphML file into the workbook.

5. Repeat step 4 for each of the other GraphML files.  The content of the other GraphML files will get appended to the workbook, because you told NodeXL not to clear the workbook first.

Two other merge techniques are discussed in "how to merge several Nodexl files together" at http://nodexl.codeplex.com/discussions/242896.

If your GraphML files contain vertex attributes, then these techniques can lead to unpredictable results and probably shouldn't be used.  That's because the Vertices worksheet could end up with multiple, conflicting rows for the same vertex.  I do not have an easy solution for you if your GraphML files contain vertex attributes.  They have to be merged using some other technique before being imported into NodeXL.

-- Tony