TensorFlow.NET/src/TensorFlowNET.Keras/Losses/CosineSimilarity.cs

namespace Tensorflow.Keras.Losses;

public class CosineSimilarity : LossFunctionWrapper
{
    protected int axis = -1;

    public CosineSimilarity(
        string reduction = null,
        int axis = -1,
        string name = null) :
        base(reduction: reduction, name: name == null ? "cosine_similarity" : name)
    {
        this.axis = axis;
    }

    public override Tensor Apply(Tensor y_true = null, Tensor y_pred = null, bool from_logits = false, int axis = -1)
    {
        Tensor y_true_normalize = nn_impl.l2_normalize(y_true, axis: this.axis);
        Tensor y_pred_normalize = nn_impl.l2_normalize(y_pred, axis: this.axis);
        return -math_ops.reduce_sum(y_true_normalize * y_pred_normalize, axis: constant_op.constant(this.axis));
    }
}