feat(F-15): citation graph — PageRank, coupling, co-citation, CLI

- codex/graph.py: build_citation_graph (DiGraph from DB), citation_pagerank
  (graceful uniform fallback < 5 nodes), find_related (bibliographic coupling),
  find_co_cited, dangling_citations
- codex/config.py: graph_cite_boost_alpha=0.3, graph_min_corpus_size=15
- codex/cli.py: graph report [--top-n] [--json], graph related <paper-id>
  [--min-shared]; search paper --cite-boost (PageRank score weighting)
- tests/graph/: 39 tests (graph functions + CLI) — 326 total green

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
This commit is contained in:
Tarik Moussa
2026-06-15 03:31:36 +02:00
parent 9647897173
commit fd51b70000
6 changed files with 747 additions and 0 deletions

View File

@@ -14,6 +14,7 @@ prov_app = typer.Typer(help="Provenance: @cite scan, code_links, bib export.")
wiki_app = typer.Typer(help="Wiki-compile: grounded concept pages over the RAG substrate.")
synth_app = typer.Typer(help="Synthesis: grounded leads and quarantined conjectures (F-13).")
quality_app = typer.Typer(help="Chunk quality gate and section classification (F-16).")
graph_app = typer.Typer(help="Citation graph analytics: PageRank, coupling, dangling leads (F-15).")
# F-09: search sub-app with paper (semantic) and formula (FTS) subcommands
search_app = typer.Typer(
help="Search: semantic paper search and formula full-text search.",
@@ -24,6 +25,7 @@ app.add_typer(prov_app, name="provenance")
app.add_typer(wiki_app, name="wiki")
app.add_typer(synth_app, name="synthesis")
app.add_typer(quality_app, name="quality")
app.add_typer(graph_app, name="graph")
app.add_typer(search_app, name="search")
@@ -66,8 +68,14 @@ def search_callback(ctx: typer.Context) -> None:
def search_paper(
query: str = typer.Argument(..., help="Natural-language search query"),
limit: int = typer.Option(10, "--limit", "-n", help="Number of results"),
cite_boost: bool = typer.Option(
False,
"--cite-boost",
help="Weight results by citation PageRank (F-15). Graceful when corpus < 5 papers.",
),
) -> None:
"""Semantic similarity search over paper abstracts."""
from codex.config import get_settings
from codex.db import get_conn
from codex.embed import get_embedder
@@ -84,6 +92,24 @@ def search_paper(
""",
{"emb": emb, "limit": limit},
).fetchall()
if cite_boost and rows:
from codex.graph import build_citation_graph, citation_pagerank
settings = get_settings()
graph = build_citation_graph(conn)
pr = citation_pagerank(graph)
alpha = settings.graph_cite_boost_alpha
results = []
for row in rows:
pr_score = pr.get(row["id"], 0.0)
boosted = row["distance"] * (1.0 + alpha * pr_score)
results.append((boosted, row))
results.sort(key=lambda x: x[0])
for boosted_dist, row in results:
typer.echo(f"[{boosted_dist:.3f}] {row['id']} ({row['year']}) — {row['title']}")
return
for row in rows:
typer.echo(f"[{row['distance']:.3f}] {row['id']} ({row['year']}) — {row['title']}")
@@ -496,3 +522,84 @@ def quality_run(
f"{stats['removed']} removed, "
f"{stats['tagged']} section-tagged"
)
# ---------------------------------------------------------------------------
# F-15 — graph sub-commands
# ---------------------------------------------------------------------------
@graph_app.command("report")
def graph_report(
top_n: int = typer.Option(10, "--top-n", "-n", help="Number of hub papers to show."),
output_json: bool = typer.Option(False, "--json", help="Output as JSON."),
) -> None:
"""Show citation graph report: top hub papers, dangling citations, cluster summary."""
from codex.db import get_conn
from codex.graph import build_citation_graph, citation_pagerank, dangling_citations
with get_conn() as conn:
graph = build_citation_graph(conn)
known_ids = {row["id"] for row in conn.execute("SELECT id FROM papers").fetchall()}
if graph.number_of_nodes() == 0:
typer.echo("Citation graph is empty — ingest some papers first.")
raise typer.Exit(0)
pr = citation_pagerank(graph)
hubs = sorted(pr.items(), key=lambda x: -x[1])[:top_n]
dangling = dangling_citations(graph, known_ids)
if output_json:
typer.echo(
json.dumps(
{
"nodes": graph.number_of_nodes(),
"edges": graph.number_of_edges(),
"hubs": [{"paper_id": pid, "pagerank": score} for pid, score in hubs],
"dangling_count": len(dangling),
"dangling": dangling,
},
indent=2,
)
)
return
typer.echo(f"Graph: {graph.number_of_nodes()} nodes, {graph.number_of_edges()} edges")
typer.echo("")
typer.echo(f"TOP-{top_n} HUB PAPERS (PageRank)")
typer.echo("-" * 48)
for pid, score in hubs:
typer.echo(f" {score:.4f} {pid}")
typer.echo("")
typer.echo(f"DANGLING CITATIONS ({len(dangling)} cited but not ingested)")
typer.echo("-" * 48)
for pid in dangling[:top_n]:
typer.echo(f" {pid}")
if len(dangling) > top_n:
typer.echo(f" … and {len(dangling) - top_n} more")
@graph_app.command("related")
def graph_related(
paper_id: str = typer.Argument(..., help="Paper ID to find related papers for."),
min_shared: int = typer.Option(
2, "--min-shared", help="Minimum shared references for bibliographic coupling."
),
) -> None:
"""List bibliographically related papers (shared references ≥ min-shared)."""
from codex.db import get_conn
from codex.graph import build_citation_graph, find_related
with get_conn() as conn:
graph = build_citation_graph(conn)
related = find_related(paper_id, graph, min_shared=min_shared)
if not related:
typer.echo(f"No papers with ≥ {min_shared} shared references found for {paper_id}.")
return
typer.echo(
f"Papers related to {paper_id} (bibliographic coupling, ≥ {min_shared} shared refs):"
)
for pid in related:
typer.echo(f" {pid}")

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@@ -286,6 +286,30 @@ class Settings(BaseSettings):
),
)
# ------------------------------------------------------------------
# F-15 Literature Graph
# ------------------------------------------------------------------
graph_cite_boost_alpha: float = Field(
default=0.3,
ge=0.0,
le=1.0,
description=(
"Weight of the PageRank citation-boost in hybrid search. "
"Final score = dense_score * (1 + alpha * pagerank_score). "
"Set to 0.0 to disable the boost without removing the flag."
),
)
graph_min_corpus_size: int = Field(
default=15,
gt=0,
description=(
"Minimum number of ingested papers for citation_pagerank to yield "
"meaningful rankings. Below this threshold a warning is logged and "
"uniform scores are returned."
),
)
@lru_cache(maxsize=1)
def get_settings() -> Settings:

169
codex/graph.py Normal file
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@@ -0,0 +1,169 @@
"""Citation graph analytics (F-15).
Builds an in-memory NetworkX DiGraph from the ``citations`` table and
provides PageRank, bibliographic coupling, co-citation, and dangling-
citation queries. The graph is ephemeral — rebuilt per call, < 1 s for
≤ 100 papers.
Graceful degradation
--------------------
* ``citation_pagerank`` returns uniform scores when the graph has fewer
than 5 nodes, and logs a warning.
* All functions accept an empty graph without raising.
"""
from __future__ import annotations
import logging
from typing import Any, cast
import networkx as nx
logger = logging.getLogger(__name__)
_MIN_PAGERANK_NODES = 5
def build_citation_graph(conn: Any) -> nx.DiGraph:
"""Load the ``citations`` table into a directed graph.
Nodes are paper IDs (strings). An edge ``citing → cited`` means
the citing paper references the cited paper. Both ingested papers
and dangling targets (cited but not yet ingested) appear as nodes.
Parameters
----------
conn:
Open psycopg connection (dict-row factory assumed).
Returns
-------
nx.DiGraph with every (citing_id, cited_id) pair as an edge.
"""
rows = conn.execute("SELECT citing_id, cited_id FROM citations").fetchall()
g: nx.DiGraph = nx.DiGraph()
for row in rows:
g.add_edge(row["citing_id"], row["cited_id"])
logger.debug(
"Built citation graph: %d nodes, %d edges", g.number_of_nodes(), g.number_of_edges()
)
return g
def citation_pagerank(graph: nx.DiGraph, *, damping: float = 0.85) -> dict[str, float]:
"""Compute PageRank over the citation graph.
Parameters
----------
graph:
DiGraph from :func:`build_citation_graph`.
damping:
PageRank damping factor (default 0.85).
Returns
-------
``{paper_id: score}`` dict. Scores sum to approximately 1.0.
When ``graph`` has fewer than :data:`_MIN_PAGERANK_NODES` nodes,
returns a uniform distribution and logs a warning — the signal is
too thin to be meaningful.
"""
n = graph.number_of_nodes()
if n == 0:
return {}
if n < _MIN_PAGERANK_NODES:
logger.warning(
"citation_pagerank: only %d nodes — corpus too small for meaningful ranking "
"(need ≥ %d). Returning uniform scores.",
n,
_MIN_PAGERANK_NODES,
)
uniform = 1.0 / n
return {node: uniform for node in graph.nodes()}
return cast(dict[str, float], nx.pagerank(graph, alpha=damping))
def find_related(paper_id: str, graph: nx.DiGraph, *, min_shared: int = 2) -> list[str]:
"""Bibliographic coupling: papers sharing ≥ ``min_shared`` references with ``paper_id``.
Two papers are bibliographically coupled when they cite the same sources.
The more shared references, the more likely they treat related topics.
Parameters
----------
paper_id:
Source paper whose references form the seed set.
graph:
DiGraph from :func:`build_citation_graph`.
min_shared:
Minimum number of shared references to be included.
Returns
-------
List of paper IDs ordered by shared-reference count DESC.
"""
if paper_id not in graph:
return []
# papers cited by paper_id
references: set[str] = set(graph.successors(paper_id))
if not references:
return []
shared: dict[str, int] = {}
for ref in references:
# other papers that also cite this reference
for co_citer in graph.predecessors(ref):
if co_citer == paper_id:
continue
shared[co_citer] = shared.get(co_citer, 0) + 1
return [
pid for pid, count in sorted(shared.items(), key=lambda x: -x[1]) if count >= min_shared
]
def find_co_cited(paper_id: str, graph: nx.DiGraph) -> list[tuple[str, int]]:
"""Co-citation: papers frequently cited alongside ``paper_id``.
A paper X is co-cited with ``paper_id`` when some third paper cites both.
Returns
-------
``[(paper_id, count)]`` ordered by count DESC.
"""
if paper_id not in graph:
return []
# papers that cite paper_id
citers: set[str] = set(graph.predecessors(paper_id))
if not citers:
return []
co_cited: dict[str, int] = {}
for citer in citers:
for other in graph.successors(citer):
if other == paper_id:
continue
co_cited[other] = co_cited.get(other, 0) + 1
return sorted(co_cited.items(), key=lambda x: -x[1])
def dangling_citations(graph: nx.DiGraph, known_ids: set[str]) -> list[str]:
"""Return graph nodes not present in ``known_ids`` (cited but not yet ingested).
Complements :func:`codex.discover.discovery_leads` with graph context:
the returned IDs are reachable in the citation graph but have no paper
record in the DB.
Parameters
----------
graph:
DiGraph from :func:`build_citation_graph`.
known_ids:
Set of paper IDs that exist in the ``papers`` table.
Returns
-------
List of dangling paper IDs (unordered).
"""
return [node for node in graph.nodes() if node not in known_ids]