Checking basic Graphserver functions

basic_pygs_test1.py

# Incarnate the graph database created earlier
# with the graph compiler tools
from graphserver.core import Graph, State, Link
from graphserver.graphdb import GraphDatabase
gdb = GraphDatabase('trimet_13sep2009.linked.gsdb')
g = gdb.incarnate()

# Board-alight graphs contain many vertices which do not
# correspond to stations – print a list of only the stations
# Is there a better way to do this?
# [v.label for v in g.vertices if v.label[0:3] == 'sta']

# Store a particular moment as seconds since the epoch
t0 = 1253730000
# Check it in human-readable form.
# Wed Sep 23 20:20:00 2009 (European time)
import time
time.ctime(t0)

# Tri-Met stations:
beaverton = 'sta-9979'  # Beaverton Transit Center Northbound
psquare   = 'sta-8334'  # Pioneer Square MAX Eastbound
lombard   = 'sta-3451'  # North Lombard and Mississippi (east of MAX Yellow line)
airport   = 'sta-10579' # Portland International Airport
belmont   = 'sta-430'   # SE Belmont and 42nd Westbound
denney    = 'sta-9749'  # an office park in Beaverton

# Give similar results to Tri-Met

# orig = belmont
# dest = beaverton

# orig = psquare
# dest = denney

# orig = lombard
# dest = denney

# Gives a better/faster solution than Tri-Met... 
# Because it uses the green MAX line
# which is not yet visible on their site.

orig = psquare
dest = 'sta-1561'

# Build a shortest path tree for this particular pair
# and display the results
spt = g.shortest_path_tree( orig, dest, State(1, t0))
vertices, edges = spt.path( dest )
for i in range(len(vertices)) :
    v  = vertices[i]
    vp = v.payload
    print "%s %3i %10s %15s" % (time.ctime(vp.time), vp.weight / 60, vp.trip_id, v.label),
    try: 
        e  = edges[i]
        ep = e.payload
        print type(ep).__name__
    except:
        print "ARRIVAL"

print "\nwalked %i meters, %i vehicles." % (vp.dist_walked, vp.num_transfers)

# Get a full path tree from pioneer square
# and print the times for the shortest path to every other stop
spt = g.shortest_path_tree( psquare,  None, State(1, t0))
for r in [(v.label, (v.payload.time - t0) / 60, v.payload.dist_walked, v.payload.num_transfers) for v in spt.vertices if v.label[0:3] == 'sta'] :
    print "%10s in %3i min, walked %4i meters, %1i vehicles" % r 

# Improvised stress and speed test.
# Find a full shortest path tree from every station
# and time the calculations
ti = time.time()
for vl in vlabels :
    tn = time.time()
    spt = g.shortest_path_tree(vl, None, State(1, t0))
    # About 1.8 seconds per tree for PDX linked transit graph
    print vl, time.time() - tn
    # Clean up and avoid massive memory leak
    spt.destroy() 

# Gives about 2 seconds per full path tree
print (time.time() - ti) / len(vlabels)  

# Clean up
g.destroy()

mmap_test.py

from graphserver.core import *
from graphserver.graphdb import GraphDatabase

import time
t0 = 1253730000
time.ctime(t0)

gdb = GraphDatabase('bart.linked.gsdb')
mmon()
g = gdb.incarnate()
mmoff()

orig = 'sta-12TH'
dest = 'sta-SANL'

spt = g.shortest_path_tree( orig, dest, State(1, t0))
vertices, edges = spt.path( dest )
for i in range(len(vertices)) :
    v  = vertices[i]
    vp = v.payload
    print "%s %3i %10s %15s" % (time.ctime(vp.time), vp.weight / 60, vp.trip_id, v.label),
    try: 
        e  = edges[i]
        ep = e.payload
        print type(ep).__name__
    except:
        print "ARRIVAL"

spt.destroy()