MCSN Thursday, 15-Sep-11

• Today's assignment: Read sections 1.3.3 to 1.5; submit 1.6; come to class prepared with a Pajek example drawn from the Web, and illustrating chapter content. This will be a regular Thursday assignment. This week, the ESNAP readings focussed on a directed graph, so any directed graph from the web is fine. For instance, you could extract a portion of Twitter.com "following" relations, or look at musician relations (influences, influenced by) on allmusic.com. The point is to create a directed graph in Pajek.
• More precipitation from your brainstorms
• Homework exercises from Tuesday - review
• How to create networks, partitions, and vectors in Pajek
  • Manipulating networks in Pajek itself
  • Editing Pajek files in a text processor
    • Edge and arc list formats
    • Matrix format
  • Using txt2pajek
• More combinatorics...
  • How many lines does a complete simple graph on n vertices contain?
    • Undirected graphs
    • Directed graphs
  • How many different undirected simple graphs are there on n vertices?
    • Here, "different" means "non-isomorphic".
      • A square and a trapazoid and a twisted square are all isomorphic
      • Energizing graphs in Pajek always generates an isomorphic equivalent
    • Counting:
      • numbers
      • pictures