trustrank: TrustRank Seed-Biased PageRank

In pagerankr: Modular Toolkit for PageRank Calculation

TrustRank Seed-Biased PageRank

Description

TrustRank (Gyöngyi, Garcia-Molina & Pedersen, 2004) is personalized PageRank whose teleport vector is concentrated on a set of **trusted seed** pages instead of being uniform. Trust then flows outward along links and attenuates with distance (the PageRank damping factor *is* the trust-attenuation mechanism), so pages well-linked from the trusted core score high and pages far from it score low.

'pagerankr' implements this with **no new solver**: a trusted-seed prior is exactly a 'prior_df' for the existing TIPR personalization path. Build that prior from a seed set with [seed_prior()], and 'trustrank()' is the worked convenience wrapper that builds the seed prior and runs [pagerank()] with it on the forward graph.

This is **seed-biased PageRank**, not a full spam-detection system: it reproduces the biased-propagation core of TrustRank, leaving seed selection (expert-reviewed "good" pages) to the caller.

Usage

trustrank(
  edge_list_df,
  seeds,
  seed_weight = NULL,
  seed_url_col = "url",
  seed_weight_col = "weight",
  ...
)

Arguments

edge_list_df	A data frame representing the edge list, typically with columns like "from" and "to". Edges are expected to be page-to-page hyperlinks: 'pagerank()' is graph-agnostic and treats every endpoint as a node, so resource links (images, CSS, JS, and other non-HTML references) must be filtered upstream or they collect authority as ordinary vertices. 'pagerank_screaming_frog()' does this at the crawl boundary via [sf_graph_eligible()] ('Hyperlink' only); a hand-built or non-SF edge list should apply the same hyperlink-only filter before scoring.
seeds	The trusted seed set. Either a character vector of trusted URLs (each gets equal seed weight unless 'seed_weight' is given), or a data frame with a URL column and a numeric weight column (see 'seed_url_col' / 'seed_weight_col') for unequal trust. See [seed_prior()].
seed_weight	Optional numeric trust weight for a character-vector 'seeds': either one value per seed or a single value recycled to all seeds. Ignored when 'seeds' is a data frame. Default 'NULL' (every seed weight '1', i.e. a uniform distribution over the trusted set, as in the original TrustRank).
seed_url_col, seed_weight_col	Column names used when 'seeds' is a data frame. Defaults '"url"' / '"weight"'. Ignored for a character vector.
...	Additional arguments forwarded to [pagerank()] (e.g. 'redirects_df', 'rurl_params', 'prior_transform', 'prior_alpha', 'damping'). Passing 'prior_df', 'prior_url_col', or 'prior_weight_col' is an error.

Details

The seed weights are an **additive trust budget**: when two seed URLs fold onto the same vertex (redirect/canonical variants) their weights sum, exactly as the [pagerank()] / [align_prior_to_vertices()] prior contract specifies. Equal weights reproduce TrustRank's uniform seed distribution; unequal weights express graded trust. See [seed_prior()] for the prior-builder contract; the same builder serves [topic_feeder_pagerank()], which runs it on the reversed graph.

'trustrank()' forwards '...' to [pagerank()], so the full graph-preparation surface (redirects, canonicals, URL cleaning, domain/host filtering, edge weights, duplicate-edge policy) and the prior-shaping knobs ('prior_transform', 'prior_alpha') are all available. In particular 'prior_alpha' mixes a uniform teleport baseline back in: 'prior_alpha = 0' (the default) is pure trust teleport (untrusted, unreachable pages get no teleport mass), while a small positive value gives every page a floor. Because this owns the prior, passing 'prior_df', 'prior_url_col', or 'prior_weight_col' to 'trustrank()' is an error — supply 'seeds'.

Value

The [pagerank()] result data frame ('node_name', 'pagerank', and the 'prior_weight' column the prior path adds), carrying the usual '"transition_audit"' attribute.

See Also

[seed_prior()], [pagerank()], [align_prior_to_vertices()], [topic_sensitive_pagerank()], [topic_feeder_pagerank()]

Examples

edges <- data.frame(
  from = c("/", "/", "/hub", "/hub", "/spam", "/good"),
  to = c("/hub", "/good", "/good", "/deep", "/good", "/hub")
)

# Build a trusted-seed prior, then run it through pagerank() manually.
prior <- seed_prior(c("/", "/hub"))
pr <- pagerank(edges, prior_df = prior, clean_edge_urls = FALSE)

# ...or in one call with the convenience wrapper.
tr <- trustrank(edges, c("/", "/hub"), clean_edge_urls = FALSE)
print(tr)

pagerankr documentation built on Oct. 1, 2026, 5:09 p.m.