def randbasic_trial_from_num_beacons(rb_args):
"""
Run a single randbasic trial when given the graph and number of beacons
:param rb_args is a tuple with the following:
ofname: file name for output
header_row: header for use in opening a DictWriter
trial_num: index of this trial
G: NetworkX graph object
num_beacons: number of nodes from G to use as beacons
trial_seed: main seed used for this trial
k: number of paths to probe in expectation
output: dict with partial info about this trial
edge_attr: weight attribute for edges
node_attr: weight attribute for nodes
statImp: importance weight for computing result statistics
statTol: tolerance weight for computing result statistics
This chooses a set of beacons of specified size, chooses probing paths between the set of beacons, runs a trial, computes the statistics on the probing sequence, and writes the result to ofile (after taking a lock on it so that many copies of this can be run in parallel).
"""
(ofname, header_row, trial_num, G, num_beacons, trial_seed, maxs, k, output, edge_attr, node_attr, statImp, statTol) = rb_args
# Create the RNG for this trial and seed it with the seed from the
# top-level RNG passed in the argument. Even if we don't use all these
# seeds, create them in the same order so that, e.g., sim_seed is always
# the seventh output of our trial's RNG. Save the relevant ones in
# the output dict to be written to file.
output['trialseed'] = trial_seed
output['trialnum'] = trial_num
trial_RNG = random.Random()
trial_RNG.seed(a=trial_seed)
g_seed = trial_RNG.randint(-sys.maxint - 1, sys.maxint)
b_seed = trial_RNG.randint(-sys.maxint - 1, sys.maxint)
p_seed = trial_RNG.randint(-sys.maxint - 1, sys.maxint)
w_seed = trial_RNG.randint(-sys.maxint - 1, sys.maxint)
t_seed = trial_RNG.randint(-sys.maxint - 1, sys.maxint)
res_seed = trial_RNG.randint(-sys.maxint - 1, sys.maxint)
sim_seed = trial_RNG.randint(-sys.maxint - 1, sys.maxint)
# Seeds:
# g: graph G
# b: beacons
# p: paths P
# w: weighting
# t: test set
# res: reserved for future use
# sim: simulation
output['gseed'] = g_seed
output['bseed'] = b_seed
output['pseed'] = p_seed
output['wseed'] = 'na'
output['tseed'] = 'na'
output['simseed'] = sim_seed
# Below, olock is a global lock that is shared by all processes
# running this in parallel. It is acquired before writing to the
# output file and released after the writing is done.
# Choose num_beacons beacons using a RNG seeded with b_seed
beacon_RNG = random.Random()
beacon_RNG.seed(a=b_seed)
B = beacon_RNG.sample(sorted(G.nodes()),num_beacons)
# Construct all paths in G with randomness p_seed
all_paths = jrnx.jr_all_pairs_shortest_path(G, seed=p_seed)
P = dict()
# Now select only the paths that are between (distinct) beacons
for s in B:
for d in B:
if d != s:
P.setdefault(s, dict())[d] = all_paths[s][d]
# Add weights to edges and nodes if desired
if edge_attr is not None:
weighting.add_edge_weights_from_paths(G, P, edge_attr_name=edge_attr)
weighting.add_reciprocal_weights(G, src_attr_name=edge_attr, dst_attr_name=statTol, components='edges', use_default=True, default=0)
if node_attr is not None:
weighting.add_node_weights_from_edge_mean(G, node_attr_name=node_attr, edge_attr_name=edge_attr)
weighting.add_reciprocal_weights(G, src_attr_name=node_attr, dst_attr_name=statTol, components='nodes', use_default=True, default=0)
psize = num_probing_paths(P)
p = min(1.0, float(k)/psize)
output['p'] = p
# Run a trial, with sim_seed as the randomness, to produce the
# probing sequence seq
try:
t = timer()
start_time = timer()
seq = strategy.simulate(copy.deepcopy(G), copy.deepcopy(P), p, trialseed=sim_seed, maxsteps=maxs)
output['simtime'] = timer() - start_time
except Exception as e:
output['simtime'] = timer() - start_time
output['status'] = 'Exception raised during simulate: ' + repr(e)
with olock:
with open(ofname, 'a') as csvfile:
writer = csv.DictWriter(csvfile, header_row, extrasaction='ignore')
writer.writerow(output)
return
# Compute the statistics on seq
try:
t = timer()
results = stats.all_sequence_stats(seq, P, G, importance=statImp, tolerance=statTol)
except Exception as e:
output['status'] = 'Exception raised during stats computation ' + repr(e)
with olock:
with open(ofname, 'a') as csvfile:
writer = csv.DictWriter(csvfile, header_row, extrasaction='ignore')
writer.writerow(output)
return
# Update output with the statistics and write it to file
output.update(results)
with olock:
with open(ofname, 'a') as csvfile:
writer = csv.DictWriter(csvfile, header_row, extrasaction='ignore')
writer.writerow(output)
return
def setcover_ba_trial(sc_args):
"""
Run a single setcover trial for specified B--A graph parameters
:param rb_args is a tuple with the following:
fractional: whether to use fractional version of B--A algorithm
ofname: file name for output
header_row: header for use in opening a DictWriter
trial_num: index of this trial
b: number of beacons to use
n: number of graph nodes
bam: int number of edges for each new node in B--A model
trial_seed: main seed used for this trial
alpha: setcover parameter alpha
k: number of paths to probe in expectation
output: dict with partial info about this trial; this is mutated here
edge_attr: weight attribute for edges
node_attr: weight attribute for nodes
statImp: importance weight for computing result statistics
statTol: tolerance weight for computing result statistics
This generates a B--A preferential-attachment graph, chooses beacons, computes probing paths, runs a trial, computes the statistics on the probing sequence, and writes the result to ofile (after taking a lock on it so that many copies of this can be run in parallel).
"""
(fractional, ofname, header_row, trial_num, b, n, bam, trial_seed, maxs, alpha, k, output, edge_attr, node_attr, statImp, statTol) = sc_args
# Create the RNG for this trial and seed it with the seed from the
# top-level RNG passed in the argument. Even if we don't use all these
# seeds, create them in the same order so that, e.g., sim_seed is always
# the seventh output of our trial's RNG. Save the relevant ones in
# the output dict to be written to file.
output['trialseed'] = trial_seed
output['trialnum'] = trial_num
output['fractional'] = fractional
trial_RNG = random.Random()
trial_RNG.seed(a = trial_seed)
g_seed = trial_RNG.randint(-sys.maxint - 1, sys.maxint)
b_seed = trial_RNG.randint(-sys.maxint - 1, sys.maxint)
p_seed = trial_RNG.randint(-sys.maxint - 1, sys.maxint)
w_seed = trial_RNG.randint(-sys.maxint - 1, sys.maxint)
t_seed = trial_RNG.randint(-sys.maxint - 1, sys.maxint)
res_seed = trial_RNG.randint(-sys.maxint - 1, sys.maxint)
sim_seed = trial_RNG.randint(-sys.maxint - 1, sys.maxint)
# Seeds:
# g: graph G
# b: beacons
# p: paths P
# w: weighting
# t: test set
# res: reserved for future use
# sim: simulation
output['gseed'] = g_seed
output['bseed'] = b_seed
output['pseed'] = p_seed
output['wseed'] = 'na'
output['tseed'] = 'na'
output['simseed'] = sim_seed
# Below, olock is a global lock that is shared by all processes
# running this in parallel. It is acquired before writing to the
# output file and released after the writing is done.
# Construct a B--A graph using g_seed as its randomness. Use fractional
# version as indicated by fractional parameter. Make
# sure G is connected.
if fractional:
G = jrnx.jr_fractional_barabasi_albert_graph(n,bam,seed=g_seed)
else:
G = jrnx.jr_barabasi_albert_graph(n,bam,seed=g_seed)
if not nx.is_connected(G):
output['status'] = 'G is unexpectedly not connected!'
with olock:
with open(ofname, 'a') as csvfile:
writer = csv.DictWriter(csvfile, header_row, extrasaction='ignore')
writer.writerow(output)
return
# Choose b beacons using a RNG seeded with b_seed
beacon_RNG = random.Random()
beacon_RNG.seed(a=b_seed)
beacons = beacon_RNG.sample(sorted(G.nodes()),b)
# Construct all paths in G with randomness p_seed
all_paths = jrnx.jr_all_pairs_shortest_path(G, seed=p_seed)
P = dict()
# Now select only the paths that are between (distinct) beacons
for s in beacons:
for d in beacons:
if d != s:
P.setdefault(s, dict())[d] = all_paths[s][d]
# Add weights to edges and nodes if desired
if edge_attr is not None:
weighting.add_edge_weights_from_paths(G, P, edge_attr_name=edge_attr)
weighting.add_reciprocal_weights(G, src_attr_name=edge_attr, dst_attr_name=statTol, components='edges', use_default=True, default=0)
if node_attr is not None:
weighting.add_node_weights_from_edge_mean(G, node_attr_name=node_attr, edge_attr_name=edge_attr)
weighting.add_reciprocal_weights(G, src_attr_name=node_attr, dst_attr_name=statTol, components='nodes', use_default=True, default=0)
# Run a trial, with sim_seed as the randomness, to produce the
# probing sequence seq
try:
t = timer()
start_time = timer()
seq = strategy.simulate(copy.deepcopy(G), copy.deepcopy(P), alpha=alpha, trialseed=sim_seed, k=k, maxsteps=maxs)
output['simtime'] = timer() - start_time
except Exception as e:
output['simtime'] = timer() - start_time
output['status'] = 'Exception raised during simulate: ' + repr(e)
with olock:
with open(ofname, 'a') as csvfile:
writer = csv.DictWriter(csvfile, header_row, extrasaction='ignore')
writer.writerow(output)
return
# Compute the statistics on seq
try:
t = timer()
results = stats.all_sequence_stats(seq, P, G, importance=statImp, tolerance=statTol)
except Exception as e:
output['status'] = 'Exception raised during stats computation ' + repr(e)
with olock:
with open(ofname, 'a') as csvfile:
writer = csv.DictWriter(csvfile, header_row, extrasaction='ignore')
writer.writerow(output)
return
# Update output with the statistics and write it to file
output.update(results)
with olock:
with open(ofname, 'a') as csvfile:
writer = csv.DictWriter(csvfile, header_row, extrasaction='ignore')
writer.writerow(output)
return