＃需要以下条款3至6中的帮助：批量培训代码
correct_prediction = tf.equal（pred，y） 精度= tf.reduce_mean（tf.cast（correct_prediction，tf.float32））
def train_nn（）： 将tf.Session（）设置为sess：
sess.run(init)
## this is needed to print debug statements during training.
coord = tf.train.Coordinator()
threads = tf.train.start_queue_runners(coord=coord)
x_train, x_valid = features[:num_train_examples], features[num_train_examples:]
y_train, y_valid = labels[:num_train_examples], labels[num_train_examples:]
training_costs = []
training_accs = []
validation_costs = []
validation_accs = []
best_acc = 0.
weights
biases
for epoch in range(training_epochs):
'''
We recommend you first think about how you will implement this on your own before proceeding to read any further.
HINT: You should implement the following procedure here:
An epoch is one pass through your training data
1. Keep a counter of your epoch's total cost.
You will need this to average over the batches.
2. Keep a counter of the number of correct predictions in your epoch.
You will need this to sum over the batches to calculate per epoch accuracy.
***
**对于每个批次（总共应该有num_batches个批次）
-分批培训-
3.从x_train和y_train子集您的特征和标签
例如对于批次1，您可以选择间隔[0，batch_size）中的所有示例
对于批次2，它应介于[batch_size，2 * batch_size）之间
确保将可能的分数批次计为最后一批
4.将x_batch和y_batch按摩成numpy形状的数组（size_of_batch，28）
和（size_of_batch，1）分别
5. Feed the x_batch and y_batch into your tensorflow graph and execute the optimizer, cost and pred
in order to train your model using the current batch and also get back the batch_cost and batch_predictions
6. Count the number of correct predictions for this batch and add it to the counter for the
correct predictions in the epoch**
7. Calculate your average_epoch_cost as the total_epoch_cost divided by the number of training examples
8. Append the average_epoch_cost to `training_costs`
9. Calculate your epoch_accuracy as the total number of correct predictions in your epoch
divided by the number of training examples
10. Append the epoch_accuracy to `training_accs`
--Validation--
11. Massage your validation labels (y_valid) into a numpy arrays of shape (validation_set_size, 1)
12. With y_valid and x_valid as input to your graph, calculate the validation loss and validation predictions
We are calculating validation accuracy at the end of each epoch
13. Calculate the number of correct validation predictions by comparing against your validation labels
14. Append validation costs and validation accuracy to their respective lists
15. Avoid printing a lot of debug information when you submit the assignment.
This reduces the speed of execution.
If you want to print some information every so often, you can use the following line
at the end of your epoch loop:
if epoch%display_step==0:
print("Epoch %d | Tr cost: %f | Tr accuracy %f | Va cost: %f | Va accuracy:
%f"%(epoch + 1,avg_epoch_cost, this_epoch_accuracy, batch_valid_cost, valid_accuracy))
'''
###
### YOUR CODE HERE
###
## Assuming the above part is completed, you should now use your trained model to make predictions on the test set.
_, training_cost, training_acc = sess.run([train_op, cost, accuracy], feed_dict={x:x_train, y:y_train})
validation_cost, validation_acc = sess.run([cost, accuracy], feed_dict={x:x_valid, y:y_valid})
training_costs.append(training_cost)
training_accs.append(training_acc)
validation_costs.append(validation_cost)
validation_accs.append(validation_acc)
if validation_acc > best_acc:
training_costs = [np.float64(x) for x in training_costs]
training_accs = [np.float64(x) for x in training_accs]
validation_costs = [np.float64(x) for x in validation_costs]
validation_accs = [np.float64(x) for x in validation_accs]
print("Optimization Finished!")
#
test_predictions = []
'''
HINT:
Using the `test_features` as input to your trained graph,
run the graph once more to calculate the predictions on the test set
Cast the returned numpy array into the python list called `test_predictions`
where each element has type np.float64
'''
###
### YOUR CODE HERE
###
test_predictions = sess.run(pred, feed_dict={x: test_features}).reshape(-1).astype(np.float64, copy=False)
#coord.request_stop()
#coord.join(threads)
## close TF session if open
if 'session' in locals() and sess is not None:
print('Close interactive session')
sess.close()
return training_costs, validation_costs, training_accs, validation_accs, test_predictions