def run_training():
print(FLAGS.train_or_validation)
if FLAGS.train_or_validation == 'train':
print('distorted_inputs')
data_files_ = TRAIN_FILE
images, bboxes = grasp_img_proc.distorted_inputs(
[data_files_], FLAGS.num_epochs, batch_size=FLAGS.batch_size)
else:
print('inputs')
data_files_ = VALIDATE_FILE
images, bboxes = grasp_img_proc.inputs([data_files_])
x, y, rad = bboxes_to_grasps(bboxes)
# images_np = np.array(images)
degree = inference(images) # list
# tangent of 85 degree is 11
cost = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(logits=logits, labels=Y))
optimizer = tf.train.AdamOptimizer(learning_rate=learning_rate).minimize(cost)
rad_hat_confined = tf.minimum(11., tf.maximum(-11., rad_hat))
rad_confined = tf.minimum(11., tf.maximum(-11., rad))
# Loss function
gamma = tf.constant(10.)
loss = tf.reduce_mean(tf.pow(x_hat -x, 2) +tf.pow(y_hat -y, 2) + gamma*tf.pow(rad_hat_confined - rad_confined, 2))
train_op = tf.train.AdamOptimizer(epsilon=0.1).minimize(loss)
init_op = tf.group(tf.global_variables_initializer(), tf.local_variables_initializer())
sess = tf.Session()
sess.run(init_op)
coord = tf.train.Coordinator()
threads = tf.train.start_queue_runners(sess=sess, coord=coord)
#save/restore model
d={}
l = ['w1', 'b1', 'w2', 'b2', 'w3', 'b3', 'w4', 'b4', 'w5', 'b5', 'w_fc1', 'b_fc1', 'w_fc2', 'b_fc2']
for i in l:
d[i] = [v for v in tf.get_collection(tf.GraphKeys.GLOBAL_VARIABLES) if v.name == i+':0'][0]
dg={}
lg = ['w1', 'b1', 'w2', 'b2', 'w3', 'b3', 'w4', 'b4', 'w5', 'b5', 'w_fc1', 'b_fc1', 'w_fc2', 'b_fc2', 'w_output', 'b_output']
for i in lg:
dg[i] = [v for v in tf.get_collection(tf.GraphKeys.GLOBAL_VARIABLES) if v.name == i+':0'][0]
saver = tf.train.Saver(d)
saver_g = tf.train.Saver(dg, max_to_keep=20)
#saver.restore(sess, "/root/grasp/grasp-detection/models/imagenet/m2/m2.ckpt")
saver_g.restore(sess, FLAGS.model_path)
try:
count = 0
step = 0
start_time = time.time()
while not coord.should_stop():
start_batch = time.time()
#train
if FLAGS.train_or_validation == 'train':
_, loss_value, images_np, x_value, x_model, y_value, y_model, rad_value, rad_model = \
sess.run([train_op, loss, images, x, x_hat, y, y_hat, rad, rad_hat])
duration = time.time() - start_batch
if step % 100 == 0:
print('Step %d | loss = %s\n | x = %s\n | x_hat = %s\n | y = %s\n | y_hat = %s\n | rad = %s\n | rad_hat = %s\n | (%.3f sec/batch\n') \
%(step, loss_value, x_value[:3], x_model[:3], y_value[:3], y_model[:3], rad_value[:3], rad_model[:3], duration)
if step % 1000 == 0:
filename = MODEL_SAVE_PATH + '/step_' + str(step)
if not os.path.exists(filename):
os.mkdir(filename)
saver_g.save(sess, filename + '/m4.ckpt')
# cv2.imshow('bbox', images_np[1]) ###################################
# cv2.waitKey(0)
# print(images_np[0])
if step == 100000:
sess.close()
else:
bbox_hat = grasp_to_bbox(x_hat, y_hat, rad_hat)
bbox_value, bbox_model, x_value, x_model, y_value, y_model, rad_value, rad_model = sess.run([bboxes, bbox_hat, x, x_hat, y, y_hat, rad, rad_hat])
bbox_value = np.reshape(bbox_value, -1)
bbox_value = [(bbox_value[0],bbox_value[1]),(bbox_value[2],bbox_value[3]),(bbox_value[4],bbox_value[5]),(bbox_value[6],bbox_value[7])] # bbox_value = [(bbox_value[0]*0.35,bbox_value[1]*0.47),(bbox_value[2]*0.35,bbox_value[3]*0.47),(bbox_value[4]*0.35,bbox_value[5]*0.47),(bbox_value[6]*0.35,bbox_value[7]*0.47)]
p1 = Polygon(bbox_value)
p2 = Polygon(bbox_model)
iou = p1.intersection(p2).area / (p1.area +p2.area -p1.intersection(p2).area)
angle_diff = np.abs(np.arctan(rad_model)*180/np.pi -np.arctan(rad_value)*180/np.pi)
duration = time.time() -start_batch
# if angle_diff < 30. and iou >= 0.25:
count+=1
print('image: %d | duration = %.2f | count = %d | iou = %.2f | angle_difference = %.2f' %(step, duration, count, iou, angle_diff))
print('x=',x_value,x_model,' y=',y_value, y_model,' rad=',rad_value, rad_model,')
step +=1
except tf.errors.OutOfRangeError:
print('Done training for %d epochs, %d steps, %.1f min.' % (FLAGS.num_epochs, step, (time.time()-start_time)/60))
finally:
coord.request_stop()
coord.join(threads)
sess.close()
def run_training():
print(FLAGS.train_or_validation)
if FLAGS.train_or_validation == 'train':
print('distorted_inputs')
data_files_ = TRAIN_FILE
images, bboxes = grasp_img_proc.distorted_inputs(
[data_files_], FLAGS.num_epochs, batch_size=FLAGS.batch_size)
else:
print('inputs')
data_files_ = VALIDATE_FILE
images, bboxes = grasp_img_proc.inputs([data_files_])
x, y, degree, h, w = bboxes_to_grasps(
bboxes) # x, y, tan, h, w = bboxes_to_grasps(bboxes)
# images_np = np.array(images)
x_hat, y_hat, degree_hat, h_hat, w_hat = tf.unstack(inference(images),
axis=1) # list
# x_hat, y_hat, tan_hat, h_hat, w_hat = tf.unstack(inference(images), axis=1) # list
# tangent of 85 degree is 11
# tan_hat_confined = tf.minimum(11., tf.maximum(-11., tan_hat))
# tan_confined = tf.minimum(11., tf.maximum(-11., tan))
# Loss function
gamma = tf.constant(0.001)
loss = tf.reduce_sum(
tf.pow(x_hat - x, 2) + tf.pow(y_hat - y, 2) +
gamma * tf.pow(degree_hat - degree, 2) + tf.pow(h_hat - h, 2) +
tf.pow(w_hat - w, 2))
train_op = tf.train.AdamOptimizer(epsilon=0.1).minimize(loss)
init_op = tf.group(tf.global_variables_initializer(),
tf.local_variables_initializer())
sess = tf.Session()
sess.run(init_op)
coord = tf.train.Coordinator()
threads = tf.train.start_queue_runners(sess=sess, coord=coord)
#save/restore model
d = {}
l = [
'w1', 'b1', 'w2', 'b2', 'w3', 'b3', 'w4', 'b4', 'w5', 'b5', 'w_fc1',
'b_fc1', 'w_fc2', 'b_fc2', 'w_fc2', 'b_fc2', 'w_fc3', 'b_fc3',
'w_output', 'b_output'
]
for i in l:
d[i] = [
v for v in tf.get_collection(tf.GraphKeys.GLOBAL_VARIABLES)
if v.name == i + ':0'
][0]
dg = {}
lg = [
'w1', 'b1', 'w2', 'b2', 'w3', 'b3', 'w4', 'b4', 'w5', 'b5', 'w_fc1',
'b_fc1', 'w_fc2', 'b_fc2', 'w_output', 'b_output'
]
for i in lg:
dg[i] = [
v for v in tf.get_collection(tf.GraphKeys.GLOBAL_VARIABLES)
if v.name == i + ':0'
][0]
saver = tf.train.Saver(d)
saver_g = tf.train.Saver(dg, max_to_keep=20)
#saver.restore(sess, "/root/grasp/grasp-detection/models/imagenet/m2/m2.ckpt")
saver_g.restore(sess, FLAGS.model_path)
try:
count = 0
step = 0
start_time = time.time()
while not coord.should_stop():
start_batch = time.time()
#train
if FLAGS.train_or_validation == 'train':
_, loss_value, images_np, x_value, x_model, y_value, y_model, degree_value, degree_model, h_value, h_model, w_value, w_model = sess.run(
[
train_op, loss, images, x, x_hat, y, y_hat, degree,
degree_hat, h, h_hat, w, w_hat
])
# _, loss_value, images_np, x_value, x_model, y_value, y_model, tan_value, tan_model, h_value, h_model, w_value, w_model = sess.run([train_op, loss, images, x, x_hat, y, y_hat, tan, tan_hat, h, h_hat, w, w_hat])
duration = time.time() - start_batch
if step % 100 == 0:
print(
'Step %d | loss = %s\n | x = %s\n | x_hat = %s\n | y = %s\n | y_hat = %s\n | degree = %s\n | degree_hat = %s\n | h = %s\n | h_hat = %s\n | w = %s\n | w_hat = %s\n | (%.3f sec/batch\n'
) % (step, loss_value, x_value[:3], x_model[:3],
y_value[:3], y_model[:3], degree_value[:3],
degree_model[:3], h_value[:3], h_model[:3],
w_value[:3], w_model[:3], duration)
# print('Step %d | loss = %s\n | x = %s\n | x_hat = %s\n | y = %s\n | y_hat = %s\n | tan = %s\n | tan_hat = %s\n | h = %s\n | h_hat = %s\n | w = %s\n | w_hat = %s\n | (%.3f sec/batch\n')%(step, loss_value, x_value[:3], x_model[:3], y_value[:3], y_model[:3], tan_value[:3], tan_model[:3], h_value[:3], h_model[:3], w_value[:3], w_model[:3], duration)
# cv2.imshow('bbox', images_np[1]) ###################################
# print(images_np[1])
# cv2.imwrite("./"+str(step)+".png", images_np[1]);
cv2.waitKey(1)
if step % 1000 == 0:
filename = MODEL_SAVE_PATH + '/step_' + str(step)
if not os.path.exists(filename):
os.mkdir(filename)
saver.save(sess, filename + '/m4.ckpt')
# cv2.imshow('bbox', images_np[1]) ###################################
# cv2.waitKey(0)
# print(images_np[0])
# if step == 100000:
# sess.close()
# else:
# bbox_hat = grasp_to_bbox(x_hat, y_hat, tan_hat, h_hat, w_hat)
# bbox_value, bbox_model, x_value, x_model, y_value, y_model, tan_value, tan_model, h_value, h_model, w_value, w_model = sess.run([bboxes, bbox_hat, x, x_hat, y, y_hat, tan, tan_hat, h, h_hat, w, w_hat])
# bbox_value = np.reshape(bbox_value, -1)
# bbox_value = [(bbox_value[0],bbox_value[1]),(bbox_value[2],bbox_value[3]),(bbox_value[4],bbox_value[5]),(bbox_value[6],bbox_value[7])] # bbox_value = [(bbox_value[0]*0.35,bbox_value[1]*0.47),(bbox_value[2]*0.35,bbox_value[3]*0.47),(bbox_value[4]*0.35,bbox_value[5]*0.47),(bbox_value[6]*0.35,bbox_value[7]*0.47)]
# p1 = Polygon(bbox_value)
# p2 = Polygon(bbox_model)
# iou = p1.intersection(p2).area / (p1.area +p2.area -p1.intersection(p2).area)
# angle_diff = np.abs(np.arctan(tan_model)*180/np.pi -np.arctan(tan_value)*180/np.pi)
# duration = time.time() -start_batch
# # if angle_diff < 30. and iou >= 0.25:
# count+=1
# print('image: %d | duration = %.2f | count = %d | iou = %.2f | angle_difference = %.2f' %(step, duration, count, iou, angle_diff))
# print('x=',x_value,x_model,' y=',y_value, y_model,' tan=',tan_value, tan_model,' h=', h_value, h_model,' w=', w_value, w_model)
step += 1
except tf.errors.OutOfRangeError:
print('Done training for %d epochs, %d steps, %.1f min.' %
(FLAGS.num_epochs, step, (time.time() - start_time) / 60))
finally:
coord.request_stop()
coord.join(threads)
sess.close()
def run_training():
tf.reset_default_graph()
print(FLAGS.train_or_validation)
if FLAGS.train_or_validation == 'train':
print('distorted_inputs')
data_files_ = TRAIN_FILE #datafiles is the actual tfrdata
images, bboxes = grasp_img_proc.distorted_inputs(
[data_files_], FLAGS.num_epochs, batch_size=FLAGS.batch_size)
else:
#Validation dataset
print('inputs')
data_files_ = VALIDATE_FILE
images, bboxes = grasp_img_proc.inputs([data_files_])
# These are the labels (uses the grasp_img_proc module with the disorted images), also everything is processed as bboxes as that the labels are in xy coords
x, y, tan, h, w = bboxes_to_grasps(bboxes)
# These are the outputs of the model - used for the error minimisation (uses the grasp_inf model) - outputs the grasp representation directly
x_hat, y_hat, tan_hat, h_hat, w_hat = tf.unstack(inference(images), axis=1)
# tangent of 85 degree is 11
tan_hat_confined = tf.minimum(11., tf.maximum(-11., tan_hat))
tan_confined = tf.minimum(11., tf.maximum(-11., tan))
# Loss function
gamma = tf.constant(10.)
# A custom cost function for the box regression - essentially just a custom MSE
loss = tf.reduce_sum(
tf.pow(x_hat - x, 2) + tf.pow(y_hat - y, 2) +
gamma * tf.pow(tan_hat_confined - tan_confined, 2) +
tf.pow(h_hat - h, 2) + tf.pow(w_hat - w, 2))
# Instead of stochastic gradient descent
train_op = tf.train.AdamOptimizer(epsilon=0.1).minimize(loss)
# Initiliases the variables to have the values they have been parametised by
init_op = tf.group(tf.global_variables_initializer(),
tf.local_variables_initializer())
#Create a session
sess = tf.Session()
sess.run(init_op)
#Allows for thread qeueing
coord = tf.train.Coordinator()
threads = tf.train.start_queue_runners(sess=sess, coord=coord)
#Some stuff related to plotting
#save/restore model
#d are the weights that were used to pre-train on Imagenet! - hence why it doesnt contain w_output and b_output (those would have been classification outputs)
d = {}
l = [
'w1', 'b1', 'w2', 'b2', 'w3', 'b3', 'w4', 'b4', 'w5', 'b5', 'w_fc1',
'b_fc1', 'w_fc2', 'b_fc2'
]
# Iterates through the list l, if its in the GraphKeys, store it in the tuple d
for i in l:
d[i] = [
v for v in tf.get_collection(tf.GraphKeys.GLOBAL_VARIABLES)
if v.name == i + ':0'
][0]
dg = {}
lg = [
'w1', 'b1', 'w2', 'b2', 'w3', 'b3', 'w4', 'b4', 'w5', 'b5', 'w_fc1',
'b_fc1', 'w_fc2', 'b_fc2', 'w_output', 'b_output'
]
for i in lg:
dg[i] = [
v for v in tf.get_collection(tf.GraphKeys.GLOBAL_VARIABLES)
if v.name == i + ':0'
][0]
# This essentially just saves the current models
#saver = tf.train.Saver(d)
saver_g = tf.train.Saver(dg)
#my_models/test_crash/test_crash_continuation
if FLAGS.continue_from_trained_model == 'yes':
#saver.restore(sess, "/root/grasp/grasp-detection/models/imagenet/m2/m2.ckpt")
saver_g.restore(sess, "my_models/test_save/test_save")
'''Restores a previously trained model'''
#Just a quick code to determine the ecurrent epoch
steps_per_epoch = int(708 / FLAGS.batch_size)
model_no = 0
try:
count = 0
step = 0
epoch = 0
start_time = time.time()
while not coord.should_stop():
start_batch = time.time()
if FLAGS.train_or_validation == 'train':
#so everytime the loss, x, x_hat, tan etc are called, their operations as well as their operation flows are also called implicitly - graph flow
_, loss_value, x_value, x_model, tan_value, tan_model, h_value, h_model, w_value, w_model = sess.run(
[
train_op, loss, x, x_hat, tan, tan_hat, h, h_hat, w,
w_hat
])
duration = time.time() - start_batch
#if step % 100 == 0:
#print("Step %d | loss = %s\n | x = %s\n | x_hat = %s\n | tan = %s\n | tan_hat = %s\n | h = %s\n | h_hat = %s\n | w = %s\n | w_hat = %s\n | (%.3f sec/batch\n"%(step, loss_value, x_value[:3], x_model[:3], tan_value[:3], tan_model[:3], h_value[:3], h_model[:3], w_value[:3], w_model[:3], duration))
#How come the y values are not included? - does that not matter because the x's are already being called?
if step % 110 == 0:
saver_g.save(
sess, "my_models/test_save/test_save" + str(model_no))
model_no += 1
if step % steps_per_epoch == 0:
print(
"Step %d | loss = %s\n | x = %s\n | x_hat = %s\n | tan = %s\n | tan_hat = %s\n | h = %s\n | h_hat = %s\n | w = %s\n | w_hat = %s\n | (%.3f sec/batch\n)"
% (step, loss_value, x_value[:3], x_model[:3],
tan_value[:3], tan_model[:3], h_value[:3],
h_model[:3], w_value[:3], w_model[:3], duration))
print("Current numbers of epoch: %d" % (epoch))
ani = FuncAnimation(fig, animate(epoch, loss_value), 1)
epoch += 1
plt.tight_layout()
plt.show()
#MAKE A LIVE GRAPH MAKE IT EASIER TO SEE
else:
#VALIDATION
'''wont work yet as I have not edited the grasp_img_proc file yet'''
#Converts output of NN to four corner vertices
bbox_hat = grasp_to_bbox(x_hat, y_hat, tan_hat, h_hat, w_hat)
#Gets the value of the actual vertices (randomly), bbox from NN, the actual tan and the predicted tan
bbox_value, bbox_model, tan_value, tan_model = sess.run(
[bboxes, bbox_hat, tan, tan_hat])
#Turn the bbox value into a 1D array
bbox_value = np.reshape(bbox_value, -1)
#Rescale it to the size of the 224x224 output of the neural net
bbox_value = [(bbox_value[0] * 0.35, bbox_value[1] * 0.47),
(bbox_value[2] * 0.35, bbox_value[3] * 0.47),
(bbox_value[4] * 0.35, bbox_value[5] * 0.47),
(bbox_value[6] * 0.35, bbox_value[7] * 0.47)]
#Takes in the x,y coordinates of the vertices, and creates rectangles from vertices
p1 = Polygon(bbox_value)
p2 = Polygon(bbox_model)
#Jaccard Index/ if area is greater than 25% then it counds
jaccard = p1.intersection(p2).area / (p1.area + p2.area -
p1.intersection(p2).area)
#Also if the angle is within 30 degrees of the randomly picked rectangle then:
angle_diff = np.abs(
np.arctan(tan_model) * 180 / np.pi -
np.arctan(tan_value) * 180 / np.pi)
duration = time.time() - start_batch
if angle_diff < 30. and jaccard >= 0.25:
#Add to the count of the 'correct'
count += 1
print(
'image: %d | duration = %.2f | count = %d | jaccard = %.2f | angle_difference = %.2f'
% (step, duration, count, jaccard, angle_diff))
step += 1
except tf.errors.OutOfRangeError: #some error
saver_g.save(sess, "my_models/test_save/test_save" +
str(model_no)) #Best to save it again at the end time
if FLAGS.train_or_validation == 'train':
print('Done training for %d epochs, %d steps, %.1f min.' %
(FLAGS.num_epochs, step, (time.time() - start_time) / 60))
else:
#print("Number of validation data: ", step)
error = ((1 - (count / step)) * 100)
print("\nError of %.2f%%" % (error))
finally:
coord.request_stop() #stops the threading/queueing
coord.join(threads) #rejoins the threads
sess.close()
return error
def run_training():
print(FLAGS.train_or_validation)
if FLAGS.train_or_validation == 'train':
print('distorted_inputs')
data_files_ = TRAIN_FILE
images, bboxes = grasp_img_proc.distorted_inputs(
[data_files_], FLAGS.num_epochs, batch_size=FLAGS.batch_size)
else:
print('inputs')
data_files_ = VALIDATE_FILE
images, bboxes = grasp_img_proc.inputs([data_files_])
x, y, tan, h, w = bboxes_to_grasps(bboxes)
x_hat, y_hat, tan_hat, h_hat, w_hat = tf.unstack(inference(images),
axis=1) # list
# tangent of 85 degree is 11
tan_hat_confined = tf.minimum(11., tf.maximum(-11., tan_hat))
tan_confined = tf.minimum(11., tf.maximum(-11., tan))
# Loss function
gamma = tf.constant(10.)
loss = tf.reduce_sum(
tf.pow(x_hat - x, 2) + tf.pow(y_hat - y, 2) +
gamma * tf.pow(tan_hat_confined - tan_confined, 2) +
tf.pow(h_hat - h, 2) + tf.pow(w_hat - w, 2))
train_op = tf.train.AdamOptimizer(epsilon=0.1).minimize(loss)
init_op = tf.group(tf.global_variables_initializer(),
tf.local_variables_initializer())
sess = tf.Session()
sess.run(init_op)
coord = tf.train.Coordinator()
threads = tf.train.start_queue_runners(sess=sess, coord=coord)
#save/restore model
d = {}
l = [
'w1', 'b1', 'w2', 'b2', 'w3', 'b3', 'w4', 'b4', 'w5', 'b5', 'w_fc1',
'b_fc1', 'w_fc2', 'b_fc2'
]
for i in l:
d[i] = [
v for v in tf.get_collection(tf.GraphKeys.GLOBAL_VARIABLES)
if v.name == i + ':0'
][0]
dg = {}
lg = [
'w1', 'b1', 'w2', 'b2', 'w3', 'b3', 'w4', 'b4', 'w5', 'b5', 'w_fc1',
'b_fc1', 'w_fc2', 'b_fc2', 'w_output', 'b_output'
]
for i in lg:
dg[i] = [
v for v in tf.get_collection(tf.GraphKeys.GLOBAL_VARIABLES)
if v.name == i + ':0'
][0]
saver = tf.train.Saver(d)
saver_g = tf.train.Saver(dg)
#saver.restore(sess, "/root/grasp/grasp-detection/models/imagenet/m2/m2.ckpt")
saver_g.restore(sess, FLAGS.model_path)
try:
count = 0
step = 0
start_time = time.time()
while not coord.should_stop():
start_batch = time.time()
#train
if FLAGS.train_or_validation == 'train':
_, loss_value, x_value, x_model, tan_value, tan_model, h_value, h_model, w_value, w_model = sess.run(
[
train_op, loss, x, x_hat, tan, tan_hat, h, h_hat, w,
w_hat
])
duration = time.time() - start_batch
if step % 100 == 0:
print(
'Step %d | loss = %s\n | x = %s\n | x_hat = %s\n | tan = %s\n | tan_hat = %s\n | h = %s\n | h_hat = %s\n | w = %s\n | w_hat = %s\n | (%.3f sec/batch\n'
) % (step, loss_value, x_value[:3], x_model[:3],
tan_value[:3], tan_model[:3], h_value[:3],
h_model[:3], w_value[:3], w_model[:3], duration)
if step % 1000 == 0:
saver_g.save(sess, FLAGS.model_path)
else:
bbox_hat = grasp_to_bbox(x_hat, y_hat, tan_hat, h_hat, w_hat)
bbox_value, bbox_model, tan_value, tan_model = sess.run(
[bboxes, bbox_hat, tan, tan_hat])
bbox_value = np.reshape(bbox_value, -1)
bbox_value = [(bbox_value[0] * 0.35, bbox_value[1] * 0.47),
(bbox_value[2] * 0.35, bbox_value[3] * 0.47),
(bbox_value[4] * 0.35, bbox_value[5] * 0.47),
(bbox_value[6] * 0.35, bbox_value[7] * 0.47)]
p1 = Polygon(bbox_value)
p2 = Polygon(bbox_model)
iou = p1.intersection(p2).area / (p1.area + p2.area -
p1.intersection(p2).area)
angle_diff = np.abs(
np.arctan(tan_model) * 180 / np.pi -
np.arctan(tan_value) * 180 / np.pi)
duration = time.time() - start_batch
if angle_diff < 30. and iou >= 0.25:
count += 1
print(
'image: %d | duration = %.2f | count = %d | iou = %.2f | angle_difference = %.2f'
% (step, duration, count, iou, angle_diff))
step += 1
except tf.errors.OutOfRangeError:
print('Done training for %d epochs, %d steps, %.1f min.' %
(FLAGS.num_epochs, step, (time.time() - start_time) / 60))
finally:
coord.request_stop()
coord.join(threads)
sess.close()