cosineSimilarity static method

double cosineSimilarity(List<double> a, List<double> b)

Compute cosine similarity between two feature vectors.

Returns a value between -1.0 and 1.0, where 1.0 means identical.

Implementation

static double cosineSimilarity(List<double> a, List<double> b) {
  if (a.length != b.length || a.isEmpty) return 0.0;

  var dot = 0.0;
  var normA = 0.0;
  var normB = 0.0;

  for (var i = 0; i < a.length; i++) {
    dot += a[i] * b[i];
    normA += a[i] * a[i];
    normB += b[i] * b[i];
  }

  final denominator = sqrt(normA) * sqrt(normB);
  if (denominator == 0) return 0.0;

  return dot / denominator;
}