From 3fe37224ccc2500e7e767e5fc00163ef61182828 Mon Sep 17 00:00:00 2001
From: Jonas Knobloch <jonas.knobloch@t-online.de>
Date: Fri, 17 Apr 2026 16:07:14 +0200
Subject: Add sander module

---
 research/sander/analyze.go | 49 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 research/sander/analyze.go

(limited to 'research/sander/analyze.go')

diff --git a/research/sander/analyze.go b/research/sander/analyze.go
new file mode 100644
index 0000000..c58195d
--- /dev/null
+++ b/research/sander/analyze.go
@@ -0,0 +1,49 @@
+package sander
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+)
+
+var (
+	sqlSimilarity = `
+		CREATE TABLE similarity_buffer AS
+		WITH centroid AS (
+		    SELECT list(avg_val ORDER BY idx)::FLOAT[768] AS vec
+		    FROM (
+		        SELECT idx, avg(val) AS avg_val
+		        FROM embeddings
+		        CROSS JOIN LATERAL UNNEST(embedding::FLOAT[]) WITH ORDINALITY AS t(val, idx)
+		        WHERE reference = true
+		        GROUP BY idx
+		    )
+		)
+		SELECT e.token_id, array_distance(e.embedding, c.vec) AS distance
+		FROM embeddings e, centroid c
+`
+)
+
+func (e *Experiment) Analyze(db *sql.DB) error {
+	ctx := context.Background()
+
+	var tx *sql.Tx
+
+	if t, err := db.BeginTx(ctx, nil); err != nil {
+		return err
+	} else {
+		tx = t
+	}
+
+	defer tx.Rollback()
+
+	if _, err := tx.ExecContext(ctx, `DROP TABLE IF EXISTS similarity_buffer`); err != nil {
+		return err
+	}
+
+	if _, err := tx.ExecContext(ctx, sqlSimilarity); err != nil {
+		return fmt.Errorf("similarity: %w", err)
+	}
+
+	return tx.Commit()
+}
-- 
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