LFR_gen.py

import os
import networkx as nx
import time
import Parameters
from Parameters import *
import Display_graph
import Run_test

SEED = 2 # Root seed used for RNG. Modify if running multiple times with the same set of parameters.
MAXTRIES = 10 # Maximum tries to generate a graph using different seeds
RECREATE_FILES = False # Whether or not to overwrite existing networks with the exact same parameters
RUN_TESTS = False # Set to True to automatically run 'Run_test.py' after the graph is generated
DISPLAY_GRAPH = False # Set to True to automatically run 'Display_graph.py' after the graph is generated

# Simple xorshift for RNG
def xorshift(seed):
    x = seed
    x ^= x << 13
    x ^= x >> 17
    x ^= x << 5
    return x


# Generate one network with the specified parameters
# Returns True if it ran and False if not (if RECREATE_FILES is True the file already existed)
def generate_LFR(runNum, n, name, params, seed):
    # Set the path and file name
    path = os.path.join("Graphs", "LFR", name)
    name = "LFR_" + name + "_" + str(n) + "_" + str(runNum)
    os.makedirs(path, exist_ok = True)

    # Verify if results file already exists
    if os.path.isfile(os.path.join(path, name + ".txt")) and not RECREATE_FILES:
        return False

    params["seed"] = seed

    print(runNum, n, name, seed)

    start = time.time()

    # Generate the graph
    G = nx.LFR_benchmark_graph(n, **params)

    end = time.time()

    # Remove self loops
    #G.remove_edges_from(nx.selfloop_edges(G))

    # Return total number of communities in G
    communities = list({frozenset(G.nodes[v]["community"]) for v in G})
    print("Number of communities:", len(communities))

    # Save the communities in a list as pairs of (node, community)
    community_labels = []
    for i in range(len(communities)):
        for v in communities[i]:
            community_labels.append((v,i))
    community_labels.sort() # might not be necessary but is nice for layout.

    # Export paramters and time
    with open(os.path.join(path, name + "_params.txt"), "w") as file:
        file.write("n: " + str(n) + "\n")
        for key, value in params.items():
            if key != "seed":
                file.write(key + ": " + str(value) + "\n")
        file.write("seed: " + str(seed) + "\n")
        file.write("Number of communities: " +  str(len(communities)) + "\n")
        file.write("Time taken: " + str(round(end - start, 2)) + "s")

    # Export graph to .txt file
    nx.write_edgelist(G, os.path.join(path, name + ".txt"), data = False)

    # Write the community labels to a file
    labelsFile = os.path.join(path, name + "_labels.txt")
    with open(labelsFile, "w") as file:
        for v in community_labels:
            file.write(str(v[0]) + " " + str(v[1]) + "\n")

    # Write the communities to each line
    with open(os.path.join(path, name + "_cmty.txt"), "w") as file:
        for community in communities:
            for node in community:
                file.write(str(node) + " ")
            file.write("\n")

    # Automatically display network
    if DISPLAY_GRAPH:
        Display_graph.display_graph(os.path.join(path, name + ".txt"))

    # Automatically run tests
    if RUN_TESTS:
        Run_test.run_test(name, path, labelsFile)

    return True


#Start timer
totalTime = time.time()
totalFails = 0
lastError = None

for i in range(NUM_SAMPLES):
    genSeed = (i+1) * SEED
    for size in SIZES:
        for name, params in Parameters.params.items():
            #sometimes it works, sometimes it does not. Seems very dependent of the seed
            tries = 0
            seed = genSeed
            ran = False

            #Start timer
            start = time.time()

            while tries < MAXTRIES:
                try:
                    ran = generate_LFR(i+1, size,  name, params, seed)
                    tries = MAXTRIES+1
                except Exception as e:
                    seed = xorshift(seed)
                    tries += 1
                    lastError = e
                    continue
                except KeyboardInterrupt:
                    seed = xorshift(seed)
                    tries += 1
                    continue

            # End timer and display time
            if ran:
                end = time.time()
                print("Time taken:" + str(round(end - start, 2)) + "s\n")
            
            if tries == MAXTRIES:
                print("Could not generate", i+1, size,  name, params)
                print("ERROR: '" + str(lastError) + "'")
                totalFails += 1

print("Done. Total time:", str(round(time.time() - totalTime, 2)), "s - Total fails:", totalFails)