def sparse_accuracy(self, y_true, y_pred): """训练过程中显示逐帧准确率的函数,排除了mask的影响 此处y_true需要是整数形式(非one hot) """ # 导出mask并转换数据类型 mask = K.all(K.greater(y_pred, -1e6), axis=2) mask = K.cast(mask, K.floatx()) # y_true需要重新明确一下shape和dtype y_true = K.reshape(y_true, K.shape(y_pred)[:-1]) y_true = K.cast(y_true, 'int32') # 逐标签取最大来粗略评测训练效果 y_pred = K.cast(K.argmax(y_pred, 2), 'int32') isequal = K.cast(K.equal(y_true, y_pred), K.floatx()) return K.sum(isequal * mask) / K.sum(mask)
def dense_loss(self, y_true, y_pred): """y_true需要是one hot形式 """ # 导出mask并转换数据类型 mask = K.all(K.greater(y_pred, -1e6), axis=2, keepdims=True) mask = K.cast(mask, K.floatx()) # 计算目标分数 y_true, y_pred = y_true * mask, y_pred * mask target_score = self.path_score(y_pred, y_true) # 递归计算log Z init_states = [y_pred[:, 0]] y_pred = K.concatenate([y_pred, mask], axis=2) input_length = K.int_shape(y_pred[:, 1:])[1] log_norm, _, _ = K.rnn(self.log_norm_step, y_pred[:, 1:], init_states, input_length=input_length) # 最后一步的log Z向量 log_norm = K.logsumexp(log_norm, 1) # logsumexp得标量 # 计算损失 -log p return log_norm - target_score
def call(self, inputs): clf, x_pre, x_next = inputs uncertain = normal_shannon_entropy(clf, num_classes) cond = K.greater(self.speed, uncertain) x = K.switch(cond, x_pre, x_next) return K.in_train_phase(x_next, x)