Gephi Gephi is a tool for exploring and understanding graphs. Like Photoshop (but for graphs), the user interacts with the representation, manipulate the structures, shapes and colors to reveal hidden properties. http://gephi.org @BeatrizPatraca

Open files in Gephi In the Gephi menu bar go to File Menu and Open the .gdf file When your file is opened, the report sum up data found and issues. Click OK @BeatrizPatraca

My first representation First, you can see a hairball like this: @BeatrizPatraca

Data laboratory Open ‘data laboratory’ and check the matrix: Edges, nodes and attributes. @BeatrizPatraca

Run a layout Locate the layout module on the left panel Select Force Atlas You can see the layout properties below. Click on Run and Stop. @BeatrizPatraca

Control the layout The purpose of layout properties is to let you control the algorithm in order to make a readable representation. Force Atlas makes the connected nodes attracted to each other and pushes de unconnected nodes apart to create clusters of connections. @BeatrizPatraca

Control the layout Set the repulsion strength at 10 000 to expand the graph Click enter to validate the value. Click stop when it seems as if you have some distinct clusters. Repulsion strength: How strongly each pair of connected nodes attracted each other. @BeatrizPatraca

Control the layout You should now see a graph with the layout applied. @BeatrizPatraca

Ranking (degree) Appearance module lets you configure node’s color and size. Choose: Color  Nodes  Attribute in the top left module and choose Degree from the dropdown menu. Click on Apply. Remember: degree=number of connections. Color Size @BeatrizPatraca

Ranking (color) Let’s configure colors. Hover your mouse over the gradient bar then double click on each triangle. Try to use a bright colors for the highest degree so it’s easy to see who’s the most connected. Click on apply @BeatrizPatraca

Statistics Click the statistics tab in the top right module. Click run next to average path length. Select directed or undirected and click ok @BeatrizPatraca

My Statistics When finished the metric displays its result in a report like this (betweenness, closeness and eccentricity): @BeatrizPatraca

Data laboratory Now, the main centrality measures appear in Data laboratory tab. @BeatrizPatraca

Appearence (size) Click on the icon for size. Set min size at 10 and max size at 50. Play around with these numbers depending on the size of your network. @BeatrizPatraca

Appearance (Betweenness) Return to appearance in the top left module and choose a rank parameter from the dropdown menu: Betweenness centrality Click on the icon for size. Set min size at 10 and max size at 50. Play around with these numbers depending on the size of your network. @BeatrizPatraca

My network (betweenness and size) Color: Degree Size: Betweenness centrality metric @BeatrizPatraca

Labels In the bottom of the “Overview Window” click on the tool square and select the label that you need. @BeatrizPatraca

Labels Display node labels Set label size proportional with node size Use the slider to adjust the overall label size to your liking. You can also change the font style by clicking next to the slider @BeatrizPatraca

My labels @BeatrizPatraca

Community detection Go back to the statistics panel and click Run near the “Modularity”. Check “randomize” and click ok. @BeatrizPatraca

Partition The community detection algorithm created a “Modularity class” for each node, which we’ll use to colorize the communities. Locate the appearance module on the left panel and click on attribute and color. @BeatrizPatraca

Partition Choose “modularity class” from the dropdown menu. You can click “randomize colors” if you don’t like the colors. Click apply to colorize. @BeatrizPatraca

My partition @BeatrizPatraca

Filter Go to the filters in the top right module and open the “topology” folder. Drag the “degree range” filter in to the “Queries” and drop it to “drag filter here”. Click on the “degree range” to activate the filter. It shows a range slider and the chart that represents the data, the degree distribution here. Move the slide to sets its lower bound to 2 and filter. Nodes with a degree inferior to 2 are now hidden. @BeatrizPatraca

Preview At the very top left click on the preview tab. Under node set check “show labels” and click refresh at the bottom. Click on the presets list and try different configurations. @BeatrizPatraca

My preview @BeatrizPatraca

Networks (some representations) @BeatrizPatraca

Export Choose to export at the bottom left in either SVF or PDF. Now you have visualized your facebook network community clusters! @BeatrizPatraca

Based on: http://www.slideshare.net/sociomantic/facebook-network-analysis-using-gephi-3996673 http://gephi.org/2010/quick-start-tutorial/ http://gephi.org/2011/new-tutorial-layouts-in-gephi/ Gephi website Gephi Wiki Gephi forum @BeatrizPatraca

@BeatrizPatraca