def cross_class_label_fn(A):
    """
    This function take the matrix of size (num_classes, batch_size) and return the cross-class label matrix
    in which Yij are the elements where i,j are class indices.
    :param A: The input matrix of size (num_classes, batch_size).
    :return: The output matrix of size (num_classes, batch_size, batch_size).
    """
    label_class_i = tf.reshape(A, [num_classes, 1, FLAGS.batch_size])
    label_class_j = tf.reshape(label_class_i, [num_classes, FLAGS.batch_size, 1])
    returned_mat = tf.matmul(label_class_j, label_class_i)
    return returned_mat

    This function take the matrix of size (num_classes, batch_size) and return the cross-class label matrix
    in which Yij are the elements where i,j are class indices.
    :param A: The input matrix of size (num_classes, batch_size).
    :return: The output matrix of size (num_classes, batch_size, batch_size).
    
codes/2-basics_in_machine_learning/multiclass_svm/code/multiclass_svm.py