Yaoi Dirty - 4 months ago 116

Python Question

I am trying to use

`shuffle.batch`

So, could you suggest to me what is wrong with my code?

Moreover, what is a suitable value for capacity and

`min_after_dequeue`

`import tensorflow as tf`

import numpy as np

test_label = []

in_label = []

iris_TRAINING = "iris_training.csv"

iris_TEST = "iris_test.csv"

# Load datasets.

training_set = tf.contrib.learn.datasets.base.load_csv_with_header(filename=iris_TRAINING, target_dtype=np.int, features_dtype=np.float32)

test_set = tf.contrib.learn.datasets.base.load_csv_with_header(filename=iris_TEST, target_dtype=np.int, features_dtype=np.float32)

x_train, x_test, y_train, y_test = training_set.data, test_set.data, training_set.target, test_set.target

for n in y_train:

targets = np.zeros(3)

targets[int(n)] = 1 # one-hot pixs[0] is label and then use that number as index of one-hot

in_label.append(targets) #store all of label (one-hot)

training_label = np.asarray(in_label)

for i in y_test:

test_targets = np.zeros(3)

test_targets[int(i)] = 1 # one-hot pixs[0] is label and then use that number as index of one-hot

test_label.append(test_targets)

test_label = np.asarray(test_label)

x = tf.placeholder(tf.float32, [None,4]) #generate placeholder to store value of features for training

W = tf.Variable(tf.zeros([4, 3])) #weight

b = tf.Variable(tf.zeros([3])) #bias

y = tf.matmul(x, W) + b

y_ = tf.placeholder(tf.float32, [None, 3]) #generate placeholder to store value of labels

cross_entropy = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(y, y_))

train_step = tf.train.GradientDescentOptimizer(0.5).minimize(cross_entropy)

sess = tf.InteractiveSession()

# Train

tf.initialize_all_variables().run()

for i in range(5):

batch_xt, batch_yt = tf.train.shuffle_batch([x_train,training_label],batch_size=10,capacity=200,min_after_dequeue=10)

sess.run(train_step, feed_dict={x: batch_xt.eval(), y_: batch_yt.eval()})

print(i)

# Test trained model

correct_prediction = tf.equal(tf.argmax(y,1), tf.argmax(y_,1))

accuracy = tf.reduce_mean(tf.cast(correct_prediction, tf.float32))

print(sess.run(accuracy, feed_dict={x: x_test, y_: test_label}))

Answer

Shuffle_batch build :

- a queue
**Q**into which batch of your dataset will be enqueue - an operation to dequeue
**Q**and get a batch - a
**QueueRunner**to enqueue**Q**

(see here for more details)

So you don't need to call Shuffle_batch at each iteration but only one time before your loop. And you have to call `tf.train.start_queue_runners()`

after. So the end of your code should be something like :

```
sess = tf.InteractiveSession()
# Train
tf.initialize_all_variables().run()
batch_xt, batch_yt = tf.train.shuffle_batch([x_train,training_label],batch_size=10,capacity=200,min_after_dequeue=10)
tf.train.start_queue_runners()
for i in range(5):
sess.run(train_step, feed_dict={x: batch_xt.eval(), y_: batch_yt.eval()})
print(i)
# Test trained model
correct_prediction = tf.equal(tf.argmax(y,1), tf.argmax(y_,1))
accuracy = tf.reduce_mean(tf.cast(correct_prediction, tf.float32))
print(sess.run(accuracy, feed_dict={x: x_test, y_: test_label}))
```

Suitable values for capacity and min_after_dequeue depend of your available memory and I/O throughput. Capacity limits the place taken in memory of your dataset. They just could impact the computation time but not the final result (See here for more details).