Hi,

I am totally new to this and I did a fair amount of search to see if anyone else has brought up this topic. My question is: imagine I have a java program that generates a large graph in terms of vertices and edges. Obviously manual date entry in NodeXL workbook is not an option. What is the easiest way to import this raw data in NodeXL? I considered automatically generating a .csv file but it does not seem that NodeXL imports such files.  What I need is a data format where I can use to create a NodeXL compliant data file directly from the java program. Is this possible?

NodeXL imports from CSV, GraphML, open Excel workbooks, and directly from various social media network data sources including Twitter, Flcikr, Facebook, YouTube, email, and the WWW.

Your Java code could write CSV edge lists which NodeXL could then import.

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Marc

Here are a few options, in order of complexity.

1. Have your Java program write a tab-delimited file.  (I wouldn't use CSV unless you can guarantee that a vertex name will never include a comma.)  NodeXL can't read such a file directly, but you can import it into a standard Excel workbook using Excel Button, Open, and filter on Text Files.  Once you get the file into a standard Excel workbook, you can use NodeXL, Data, Import, From Open Workbook to copy the data from the standard Excel workbook to a NodeXL workbook.  It requires two steps, but if this is just an occasional task, then this is what I would do.

2. Have your Java program write a GraphML file (http://graphml.graphdrawing.org/primer/graphml-primer.html), then import it directly into a NodeXL workbook using NodeXL, Data, Import, From GraphML File.  This requires just one step, and GraphML supports edge and vertex attributes.

3. Implement a "graph data provider," which is a custom plug-in DLL that appears in NodeXL's Import menu.  See http://nodexl.codeplex.com/discussions/71182 for details.  You would have to use one of the Java-.NET bridge technologies if you wanted to do this in Java.  (I've never done that, so I don't know how hard it is.  It's easy in C# or Visual Basic .NET.)

-- Tony

Marc,

Thank you for your quick reply.

I have two related questions about using csv when importing to NodeXL:

(1) When I click on the import drop down menu I cannot seem to be able to locate any menu item that allows for importing csv format, or at least it is not clear from the name of the menu choices. Could you possibly show me which of them can be used for importing a csv files if any?

(2) When using csv, is there any way to also specify other graph properties, such as edge labels, vertex/edge colors, etc? and if so are there documentation on what format to use to specify such  properties?

Best,

K-

Tony,

Thank you for your reply. I received your note right after I submitted my reply to Mark. I will try out what you described.

Regards,

K-

K:

If you go the tab-delimited route (or the CSV route, if you enjoy courting trouble), it is indeed possible to import edge attributes when using NodeXL's Import From Open Workbook command.  It's also possible to import vertex attributes when you go that route, but it's convoluted and difficult to understand.  If you have both edge and vertex attributes, GraphML is the simpler, more elegant solution.

-- Tony

Hi Tony,

I am Very beginer to nodexl, i am generating one excel sheet from my c# code and i want to draw graph according to that excel sheet.how can i give that excel sheet to nodexl programatically can u please explain.

Because you are using C#, as opposed to Java, the language the original poster was using, you have another option available to you.  You can use the Excel object model to create a new NodeXL workbook from the NodeXLGraph.xltx template file that gets installed with NodeXL, then populate the Vertex 1 and Vertex 2 columns on the Edges worksheet in the new NodeXL workbook.

There are many resources available that explain how to use the Excel object model to manipulate Excel workbooks.  Here is just one example:

    http://www.codeproject.com/Articles/20228/Using-C-to-Create-an-Excel-Document

And here is the Microsoft documentation for the object model:

    http://msdn.microsoft.com/en-us/library/vstudio/wss56bz7(v=vs.100).aspx

One important point is that you won't be using Application.Workbooks.Add(), without an argument, to create a NodeXL workbook.  Application.Workbooks.Add() creates a plain, empty Excel workbook, which isn't what you want.  Instead you should use the version of the Add() method that takes a template path:

    String nodeXLTemplatePath = "SomeFolder\NodeXLGraph.xltx";
    Workbook newNodeXLWorkbook = Application.Workbooks.Add(nodeXLTemplatePath);

That creates a NodeXL workbook from the NodeXL template file.

You'll find NodeGraph.xltx file in NodeXL's program folder.  The program folder's location varies, but on English 64-bit computers it's at "C:\Program Files (x86)\Social Media Research Foundation\NodeXL Excel Template".

Note that you must have NodeXL installed on the computer on which you are running your own custom C# program, or this technique will not work.  If you want your program to be able to run on any computer, you will have to revert to one of the solutions I offered earlier in this discussion.

-- Tony