---
title: Procedures And Algorithms Overview
url: https://nexyron.tech/docs/cypher/procedures-and-algorithms
description: This is the part of Nexyron where the graph stops being only a place to store connected records and starts becoming an execution surface for retrieval, ranking, grouping, projectio
---

# Procedures And Algorithms Overview

## Consumer View

This is the part of Nexyron where the graph stops being only a place to store connected records and starts becoming an execution surface for retrieval, ranking, grouping, projection, and analysis.

The main practical categories are:

-   catalog and projection procedures
-   semantic and retrieval procedures
-   graph algorithms

The catalog/projection family now also includes materialized aggregate-view lifecycle procedures, which means analytical summaries can be managed as first-class Cypher objects rather than only ad hoc query outputs.

## Conceptual Explanation

Procedures matter because they let Nexyron extend normal Cypher without inventing a separate analytics DSL.

The pattern is:

1.  `CALL` a procedure
2.  `YIELD` rows
3.  feed those rows back into `MATCH`, `WITH`, `WHERE`, `RETURN`, and functions

Simple example:

```cypher
CALL nexyron.pagerank() YIELD node_id, score
MATCH (page)
WHERE id(page) = node_id
RETURN page.title AS page, score
ORDER BY score DESC
LIMIT 10
```

That lets users do things like:

-   run PageRank on a named graph and then join scores back to nodes
-   run `graph_quality` once to get cleanup, grouping, centrality, and weak-connection diagnostics for the observed or knowledge graph
-   perform semantic retrieval and then filter by graph structure or time
-   detect communities and then profile them with document metadata

## Procedure Families

-   projection and catalog procedures manage named analytical graphs and supporting metadata
-   semantic procedures expose retrieval and ranking workflows that use embeddings, vector indexes, or diversity-aware ranking
-   algorithm procedures expose centrality, traversal, similarity, community detection, flow, structure, and routing workloads

## Community Detection Is The Most Misunderstood Family

This repo now has separate pages because “community detection” is not one feature.

-   `louvain` is a fast modularity-oriented baseline
-   `leiden` is usually the better production default when partition quality matters
-   `hierarchical_leiden` preserves several resolution levels
-   `label_propagation` is the quick heuristic option
-   `slpa`, `sllpa`, and `bigclam` accept overlap instead of forcing one label
-   `infomap` is about flow and path compression
-   `graph_quality` is a bundled diagnostic procedure that computes cleanup, community, centrality, weak-node, and runtime metadata over one projected graph
-   stochastic block procedures are about structural roles and interaction patterns
-   `modularity_metric` and `conductance` score communities rather than generating them
-   `k1coloring` and `maxkcut` are partitioning tools with goals that differ from community discovery

## Recommended Reading Path

1.  read [procedures/README.md](https://nexyron.tech/docs/cypher/procedures) for the full family map
2.  read the relevant family page such as [community detection](https://nexyron.tech/docs/cypher/procedures/algorithms/community-detection)
3.  read the per-procedure page for the exact behavior, selection guidance, use cases, and limitations