May 4, 2011 at 6:06 PM
Edited May 4, 2011 at 6:11 PM
Yes, 33K vertices is a lot of nodes for most PCs.
Your strategy of removing low degree nodes (of which there are often many) is a good one.
NodeXL has two kinds of "filtering" that can sometimes cause confusion: spreadsheet and graph visualization filtering.
Spreadsheet filtering can be accomplished by editing the Vertices worksheet's "Visibility" column, setting the value = 0 for any vertex you wish to exclude from the calculations and the visualization.
This can also be accomplished via Autofill columns. Select "Vertex Visibility" and choose to map it to a value like Degree or Betweenness Centrality that will help you select just the parts of the network that are most interesting to you.
Be sure to select the options for this setting:
Your setting should set a value higher than zero! The higher the value, the few the vertices that will remain on the graph.
When a vertex is set to "Skip" it will be excluded from calculations and display in the network visualization.
Graph Visualization Filtering is accomplished through the Dynamic Filters dialog box access from the visualization pane. This feature removes edges and vertices from view, but not from the metrics calculations. These vertices are also using up
RAM and slow down layouts!
The best way to deal with very large network data sets is probably to filter them before importing into NodeXL, since even those edges and vertices set to Visibility = 0 will consume space in the workbook.