def algorithm2(i, g):
while (True):
aggregates = g.aggregateMessages(F.collect_set(AM.msg).alias("agg"),
sendToDst=F.when(
AM.src['value'] == -1,
AM.src["id"]))
new_vertices = g.vertices.join(
aggregates, on="id", how="left_outer").withColumn(
"newValue",
getid_maximum_udf2("id", "agg", lit(i),
"value")).drop("agg").withColumn(
'max_by_rows',
greatest('value', 'newValue')).drop(
"value",
"newValue").withColumnRenamed(
"max_by_rows", "value")
cached_new_vertices = AM.getCachedDataFrame(new_vertices)
g = GraphFrame(cached_new_vertices, g.edges)
i += 1
g.vertices.show()
if (g.filterVertices(
"value == -1").dropIsolatedVertices().edges.count() == 0):
final_df = g.vertices
final_df = final_df.withColumn(
"value",
F.when(final_df["value"] == -1,
i).otherwise(final_df["value"]))
break
return final_df
def do_triangles(conf: Conf, g: graphframes.GraphFrame, s: Stepper,
vertices_count: int) -> None:
"""
Pattern for batch oriented iteration
- we split the graph into batches using the filterVertices mechanism
- we mark the total count of triangles and the partial count
- in case of error:
* we double the number of batches and the batch number
* we restart the iteration at this point with smaller subgraph
"""
full_set = vertices_count
batches = conf.batches_for_triangles
total_triangles = conf.count_at_restart
batch = conf.batch_at_restart
subset = int(full_set / batches)
while batch < batches:
st = Stepper()
count = 0
try:
print("try batches=", batches, "subset=", subset, "at batch=",
batch)
gc.collect()
# g1 = g.filterVertices("int(cell/{}) == {}".format(subset, batch))
g1 = g.filterVertices("int(id/{}) == {}".format(subset, batch))
triangles = g1.triangleCount()
st.show_step("partial triangleCount")
gc.collect()
count = triangles.agg({"cell": "sum"}).toPandas()["sum(cell)"][0]
st.show_step("partial triangleCount sum")
total_triangles += count
print("batch=", batch, "vertices=", g1.vertices.count(), "edges=",
g1.edges.count(), "total=", total_triangles, "partial",
count)
except:
print("memory error")
batches *= 2
batch *= 2
subset = int(full_set / batches)
print("restarting with batches=", batches, "subset=", subset,
"at batch=", batch)
if subset >= 1:
continue
break
batch += 1
s.show_step("triangleCount")
print("total=", total_triangles)
# Find the youngest user's age in the graph.
g.vertices.groupBy().min("age").show()
# Count the number of "follows" in the graph.
numFollows = g.edges.filter("relationship = 'follow'").count()
# motif finding
motifs = g.find("(a)-[e]->(b); (b)-[e2]->(c)").filter("a.id != c.id")
motifs = g.find("(a)-[e]->(b); (b)-[e2]->(a)")
motifs.show()
# More complex queries
motifs.filter("b.age > 30").show()
print("\ngenerate subgraph --- ")
g1 = (g.filterVertices("age > 30").filterEdges(
"relationship = 'friend'").dropIsolatedVertices())
g1.vertices.show()
g1.edges.show()
# Breadth-first search (BFS)
print("\n BFS")
paths = g.bfs(
"name = 'Esther'",
"age < 32",
edgeFilter="relationship != 'friend'",
maxPathLength=3,
).show()
# In-Degree and Out-Degree Metrics
print("\n Degree--------------")
inDeg = g.inDegrees
tmp = []
for i in range(len(msg_ids)):
tmp.append(int(msg_ids[i]))
if max(tmp) < int(id):
return superstep
else:
return -1
check_max_udf = F.udf(check_max, types.IntegerType())
superstep = 1
while (1):
sub_g = g.filterVertices("color == -1")
#only one vertice left uncolored
if (sub_g.vertices.count() == 1):
res = sub_g.vertices.withColumn("newColor",
lit(superstep)).drop("color")
#color remaining vertice
new_vertices = g.vertices.join(res, on="id", how="left_outer") \
.withColumnRenamed("color", "oldColor") \
.withColumn("color", get_max_udf(F.col("oldColor"), F.col("newColor"))) \
.drop("oldColor").drop("newColor")
print("------------ Graph Coloring Solution ------------")
cached_new_vertices = AM.getCachedDataFrame(new_vertices)
g = GraphFrame(cached_new_vertices, g.edges)
