1 files changed, 62 insertions, 0 deletions
diff --git a/rag/vector.go b/rag/vector.go
new file mode 100644
index 0000000..7a69a1b
--- /dev/null
+++ b/rag/vector.go
@@ -0,0 +1,62 @@
+package rag
+
+import (
+	"errors"
+	"math"
+)
+
+const isNormalizedPrecisionTolerance = 1e-6
+
+// dotProduct calculates the dot product between two vectors.
+// It's the same as cosine similarity for normalized vectors.
+// The resulting value represents the similarity, so a higher value means the
+// vectors are more similar.
+func dotProduct(a, b []float32) (float32, error) {
+	// The vectors must have the same length
+	if len(a) != len(b) {
+		return 0, errors.New("vectors must have the same length")
+	}
+
+	var dotProduct float32
+	for i := range a {
+		dotProduct += a[i] * b[i]
+	}
+
+	return dotProduct, nil
+}
+
+func normalizeVector(v []float32) []float32 {
+	var norm float32
+	for _, val := range v {
+		norm += val * val
+	}
+	norm = float32(math.Sqrt(float64(norm)))
+
+	res := make([]float32, len(v))
+	for i, val := range v {
+		res[i] = val / norm
+	}
+
+	return res
+}
+
+// subtractVector subtracts vector b from vector a in place.
+func subtractVector(a, b []float32) []float32 {
+	res := make([]float32, len(a))
+
+	for i := range a {
+		res[i] = a[i] - b[i]
+	}
+
+	return res
+}
+
+// isNormalized checks if the vector is normalized.
+func isNormalized(v []float32) bool {
+	var sqSum float64
+	for _, val := range v {
+		sqSum += float64(val) * float64(val)
+	}
+	magnitude := math.Sqrt(sqSum)
+	return math.Abs(magnitude-1) < isNormalizedPrecisionTolerance
+}