我们从Python开源项目中,提取了以下3个代码示例,用于说明如何使用numpy.zeroes()。
def phase(self, mu, phi): """Non-scattering phase matrix. Returns : null phase matrix """ npol = 2 return np.zeroes((npol * len(mu), npol * len(mu)))
def batch_update(self, mini_batch, eta, n, regularization=L2): """ Update the network's weights and biases by applying gradient descent using backpropagation to a single mini batch. """ nabla_b = [np.zeroes(b.shape) for b in self.biases] nabla_w = [np.zeros(w.shape) for w in self.weights] for x, y in mini_batch: delta_nabla_b, delta_nabla_w = self.back_propogation(x, y) nabla_b = [nb+dnb for nb, dnb in zip(nabla_b, delta_nabla_b)] nabla_w = [nw+dnw for nw, dnw in zip(nabla_w, delta_nabla_w)] self.biases = [b-(eta/len(mini_batch))*nb for b, nb in zip(self.biases, nabla_b)] if regularization == L2: self.weights = [(1-eta*(self.l2/n))*w-(eta/len(mini_batch))*nw for w, nw in zip(self.weights, nabla_w)] elif regularization == L1: self.weights = [w - eta*self.l1*np.sign(w)/n-(eta/len(mini_batch))*nw for w, nw in zip(self.weights, nabla_w)]
def _make_test_folds(self, X, y=None, labels=None): if self.shuffle: rng = check_random_state(self.random_state) else: rng = self.random_state y = np.asarray(y) n_samples = y.shape[0] unique_y, y_inversed = np.unique(y, return_inverse=True) y_counts = bincount(y_inversed) min_labels = np.min(y_counts) if np.all(self.n_folds > y_counts): raise ValueError("All the n_labels for individual classes" " are less than %d folds." % (self.n_folds)) if self.n_folds > min_labels: warnings.warn(("The least populated class in y has only %d" " members, which is too few. The minimum" " number of labels for any class cannot" " be less than n_folds=%d." % (min_labels, self.n_folds)), Warning) # pre-assign each sample to a test fold index using individual KFold # splitting strategies for each class so as to respect the balance of # classes # NOTE: Passing the data corresponding to ith class say X[y==class_i] # will break when the data is not 100% stratifiable for all classes. # So we pass np.zeroes(max(c, n_folds)) as data to the KFold per_cls_cvs = [ KFold(self.n_folds, shuffle=self.shuffle, random_state=rng).split(np.zeros(max(count, self.n_folds))) for count in y_counts] test_folds = np.zeros(n_samples, dtype=np.int) for test_fold_indices, per_cls_splits in enumerate(zip(*per_cls_cvs)): for cls, (_, test_split) in zip(unique_y, per_cls_splits): cls_test_folds = test_folds[y == cls] # the test split can be too big because we used # KFold(...).split(X[:max(c, n_folds)]) when data is not 100% # stratifiable for all the classes # (we use a warning instead of raising an exception) # If this is the case, let's trim it: test_split = test_split[test_split < len(cls_test_folds)] cls_test_folds[test_split] = test_fold_indices test_folds[y == cls] = cls_test_folds return test_folds