Creating a new summary graph from an old one...

pacer_rewrite_test.rb

#
# The purpose of this script is to experiment with Pacer/Tinkerpop stack for 
# graph transformation. In it we will summarize a much larger graph to produce
# a new, smaller graph that can fit into RAM via TinkerGraph for more rapid, 
# real-time analysis.
#

require 'rubygems'
require 'pacer'
require 'pacer-neo4j'

graph = Pacer.neo4j "/tmp/neo4j"

# Summarize relationships by computing raw, non-normalized weights between them
# - the number of emails sent and successfully recieved between each ego.
senders = graph.v.filter {|v| v[:type] == 'Email Address'}
groupings = senders.group.
    key_route { |sender| sender[:address] }.
    values_route(:sender) { |sender| sender.out_e('SENT').in_v(:type == 'Message').
    	out_e('RECEIVED_BY').in_v(:type == 'Email Address')[:address] }

result = groupings.reduce(proc { Hash.new(0) }, :sender) { |h, e| h[e] += 1; h }

puts "Summary computed..."

# To verify our results:
puts "tim.belden@enron.com => [" + result['tim.belden@enron.com'].sort{|a,b| b[1] <=> a[1]}[0][0] + ","
puts " " + result['tim.belden@enron.com'].sort{|a,b| b[1] <=> a[1]}[0][1].to_s + "]"

# Now create a new in-RAM TinkerGraph containing these summaries.
summary_graph = Pacer.tg

# Create vertices for senders
vertices = Hash.new
result.each_with_index do |sender, recipients|
	summary_graph.create_vertex :type => 'ego', :address => sender
end

# Now what?  No matter what I do, I cannot make any edges on this new graph.  I've looked at the source a lot, and I still can't pull it off.  I don't know what is expected in the create_edge call.