예제 #1
0
    class LossStorer:
        def __init__(self, X, y):
            self.loss = np.inf  # initialize the loss to very high
            # Initialize a fake NCA and variables needed to compute the loss:
            self.fake_nca = NeighborhoodComponentsAnalysis()
            self.fake_nca.n_iter_ = np.inf
            self.X, y, _ = self.fake_nca._validate_params(X, y)
            self.same_class_mask = y[:, np.newaxis] == y[np.newaxis, :]

        def callback(self, transformation, n_iter):
            """Stores the last value of the loss function"""
            self.loss, _ = self.fake_nca._loss_grad_lbfgs(
                transformation, self.X, self.same_class_mask, -1.0)
예제 #2
0
    class TransformationStorer:
        def __init__(self, X, y):
            # Initialize a fake NCA and variables needed to call the loss
            # function:
            self.fake_nca = NeighborhoodComponentsAnalysis()
            self.fake_nca.n_iter_ = np.inf
            self.X, y, _ = self.fake_nca._validate_params(X, y)
            self.same_class_mask = y[:, np.newaxis] == y[np.newaxis, :]

        def callback(self, transformation, n_iter):
            """Stores the last value of the transformation taken as input by
            the optimizer"""
            self.transformation = transformation