Sha256: 5adcd2b81c1aaa5b75a89317d6566233bc262f276c1e093952ba4c38366eb5ae
Contents?: true
Size: 1.67 KB
Versions: 13
Compression:
Stored size: 1.67 KB
Contents
LOAD common_pages FROM 'data/common_pages' AS (ip:chararray, from_path:chararray, into_path:chararray);
--
-- Build adjacency list <A pr B,C,D> from edges (<A B>, <A C>, <A D>)
--
adj_list_j = GROUP common_pages BY from_path;
adj_list = FOREACH adj_list_j GENERATE
group AS from_path,
1.0F AS pagerank:float,
common_pages.(dest) AS into_paths
;
STORE adj_list INTO 'data/pagerank/pr_iter_00';
--
-- Iterate pagerank <A pr_00 B,C,D> to become <A pr_01 B,C,D>
--
-- find partial share: A.rank / A.into_paths.length
-- dispatch <into_path partial_share> to each page
sent_shares = FOREACH adj_list GENERATE
FLATTEN(into_paths) AS path,
(float)(pagerank / (float)SIZE(into_paths)) AS share:float;
-- dispatch <from_path into_paths> to yourself, so you have the links still around
sent_edges = FOREACH adj_list GENERATE
from_path AS path, into_paths;
-- assemble all the received shared, and the self-sent edge list;
rcvd_shares = COGROUP sent_edges BY path INNER, sent_shares BY path PARALLEL $PARALLEL;
-- calculate the new rank, and emit a record that looked just like the input.
next_iter = FOREACH rcvd_shares {
raw_rank = (float)SUM(sent_shares.share);
-- treat the case that a node has no in links
damped_rank = ((raw_rank IS NOT NULL AND raw_rank > 1.0e-12f) ? raw_rank*0.85f + 0.15f : 0.0f);
GENERATE
group AS from_path,
damped_rank AS rank,
FLATTEN(sent_edges.into_paths)
; };
STORE next_iter INTO 'data/pagerank/pr_iter_01';
Version data entries
13 entries across 7 versions & 2 rubygems