MCSN Thursday, 15-Sep-11

• 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