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neuralnetwork.py
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neuralnetwork.py
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import numpy as np
import tensorflow as tf
import pandas
import time
import csv
import matplotlib.pyplot as plt
class dataset:
def __init__(self, args):
self.inputs, self.labels = None, None
self.x_train_list, self.y_train_list, self.x_test_list, self.y_test_list = [],[],[],[]
self.process_data(args)
def process_data(self, args):
try:
dataset = np.load('data'+args.csv+'.npz')
except:
df = pandas.read_csv(args.csv+'.csv')
data = df.values
m,n = data.shape
inputs, labels = [], []
header = list(df)
for ind, val in enumerate(header):
inp = np.float32(data[:,ind])
label = np.float32(val[1:].replace('_','.'))
inputs.append(inp)
labels.append(label)
np.savez('data'+args.csv+'.npz', X=inputs, y=labels)
dataset = np.load('data'+args.csv+'.npz')
self.inputs = dataset['X']
self.labels = np.reshape(dataset['y'], [-1, 1])
def add_noise(inputs, labels, aug_num):
""" Create and then add gaussian noise - zero mean and std of 0.1*||inp||_infty
[inputs] array that needs noise
[labels] labels of inputs
[aug_num] # for data augmentation
"""
inf_norm = (abs(inputs)).max(axis=1)
_, d = inputs.shape
std_v = np.transpose(np.tile(0.1*inf_norm, (d,1)))
inp = np.repeat(inputs, aug_num, axis=0)
std_v = np.repeat(std_v, aug_num, axis=0)
labels = np.repeat(labels, aug_num, axis=0)
noise = np.random.normal(loc=0,scale=std_v,size=inp.shape)
return inp+noise, labels
def split_dataset(inputs, labels, train_ratio):
""" Splits dataset into train/test sets
[train_ratio] ratio for training; ratio for testing is 1-train_ratio
"""
n = len(labels)
train_ind = int(np.floor(n*train_ratio))
x_train = inputs[0:train_ind]
y_train = labels[0:train_ind]
x_test = inputs[train_ind:n]
y_test = labels[train_ind:n]
return x_train, y_train, x_test, y_test
def shuffle(x,y):
""" Returns shuffled x and y arrays
[x],[y] list or 1D array
"""
x, y = np.array(x), np.array(y)
n_y = len(y)
index_array = np.arange(n_y)
np.random.shuffle(index_array)
sx, sy = [], []
for idx, val in enumerate(index_array):
sx.append(x[val])
sy.append(y[val])
sx, sy = np.array(sx), np.array(sy)
return sx, sy
def fclayer(x,scope,n):
""" Returns output from fully connected layer
[scope] variable scope
[n] number of neurons in next layer
"""
l = x.get_shape().as_list()[-1]
with tf.variable_scope(scope):
w = tf.get_variable('w',initializer=tf.truncated_normal([l,n],stddev=0.01))
b = tf.get_variable('b',initializer=tf.constant(0,tf.float32,[n]))
return tf.add(tf.matmul(x,w),b)
class neural_network:
def __init__(self, x, y, args):
h1 = tf.nn.relu(fclayer(x,'h1',args.n1))
self.pred = fclayer(h1,'regression',1)
self.loss = tf.reduce_mean(tf.square(tf.subtract(y, self.pred)))
tf.summary.scalar("loss", self.loss) # record scalar for tensorboard log
self.train_op = tf.train.AdamOptimizer(args.lr).minimize(self.loss)
# calculate accuracy
difference = tf.abs(self.pred - y)
correct = tf.round(difference)
correct_prediction = tf.equal(correct, tf.zeros(shape=tf.shape(correct)))
self.accuracy = tf.reduce_mean(tf.cast(correct_prediction, tf.float32))
tf.summary.scalar("accuracy", self.accuracy) # record scalar for tensorboard log
self.saver = tf.train.Saver(max_to_keep=1)
self.merge = tf.summary.merge_all()
def run(sess, X_train, y_train, X_test, y_test, args, case_str):
""" Trains model for one CV fold and returns lowest loss and accuracy for the fold
[sess] Tensorflow session
[x_train] Input array
[y_train] Labels
[x_test] Input array
[y_test] Labels
[args] Arguments from parser
[case_str] String of case# for folder-naming
"""
low_loss = 10000
n_train, input_dim = X_train.shape
n_test, _ = X_test.shape
n_batch = int(np.ceil(n_train/args.bs))
x = tf.placeholder(tf.float32, shape=[None, input_dim])
y = tf.placeholder(tf.float32, shape=[None, 1])
# Tensorflow's Dataset pipeline with reinitializable iterator: https://www.tensorflow.org/guide/datasets
train_dataset = tf.data.Dataset.from_tensor_slices((x,y)).shuffle(100).batch(args.bs).repeat()
test_dataset = tf.data.Dataset.from_tensor_slices((x,y)).batch(n_test)
iterator = tf.data.Iterator.from_structure(train_dataset.output_types, train_dataset.output_shapes)
features, labels = iterator.get_next()
train_init_op = iterator.make_initializer(train_dataset)
test_init_op = iterator.make_initializer(test_dataset)
# initialize model
model = neural_network(features,labels,args)
sess.run(tf.global_variables_initializer())
# save tensorboard logs
train_writer = tf.summary.FileWriter( './modelselection'+case_str+'/logs/train', sess.graph)
test_writer = tf.summary.FileWriter( './modelselection'+case_str+'/logs/test', sess.graph)
# track training time and test time
traintime = 0
time_test = []
for i in range(args.n_epochs):
tracker = i+1
sess.run(train_init_op, feed_dict = {x : X_train, y: y_train})
loss_total = 0
for j in range(n_batch):
start_train = time.clock()
_, train_loss, train_acc, summary = sess.run([model.train_op, model.loss, model.accuracy, model.merge])
end_train = time.clock()
traintime = traintime + end_train - start_train
loss_total += train_loss
sess.run(test_init_op, feed_dict = {x : X_test, y: y_test})
start_test = time.clock()
test_loss, test_acc, test_pred, summary1 = sess.run([model.loss, model.accuracy, model.pred, model.merge])
end_test = time.clock()
time_test.append(end_test-start_test)
print('epoch'+str(i))
print(train_loss)
print(test_loss)
print(test_acc)
if low_loss > test_loss:
index = sess.run(tf.argmax(tf.abs(y_test-test_pred)))
low_loss = test_loss
low_epoch = i
low_accuracy = test_acc
low_test_pred, low_y = test_pred[index], y_test[index]
savePath = model.saver.save(sess, 'modelselection'+case_str+'/checkpoint/my_model.ckpt')
print('checkpoint saved....................................')
# write tensorboard logs
train_writer.add_summary(summary, tracker)
test_writer.add_summary(summary1, tracker)
av_testtime = sum(time_test)/len(time_test)
return low_loss, low_accuracy, low_epoch, low_test_pred, low_y, traintime, av_testtime
if __name__ == "__main__":
import argparse
parser = argparse.ArgumentParser()
parser.add_argument('--csv', type=str, default='case1', help='csv filename without the .csv')
parser.add_argument('--noise', action='store_true', help='adds noise')
parser.add_argument('--n_aug', type=int, default=100, help='number to augment per training example')
parser.add_argument('--n_epochs', type=int, default=500, help='number of epochs')
parser.add_argument('--n1', type=int, default=45, help='number of hidden neurons')
parser.add_argument('--bs', type=int, default=8, help='batch size')
parser.add_argument('--lr', type=float, default=5e-4, help='learning rate')
parser.add_argument('--gamma', type=float, default=0.001, help='gamma')
args = parser.parse_args()
data = dataset(args)
X, y = shuffle(data.inputs, data.labels)
train_ratio = 0.8
x_train, y_train, x_test, y_test = split_dataset(X, y, train_ratio)
# unique folder name for each case
case_str = args.csv
if args.noise:
case_str = 'case'+str(int(case_str[4])+3)
with tf.Session() as sess:
sess.run(tf.global_variables_initializer())
# add noise and augment training if noise is True
if args.noise:
x_train, y_train = add_noise(x_train, y_train, args.n_aug)
x_test, y_test = add_noise(x_test, y_test, 1)
# train ANN and return evaluation results
loss, accuracy, epoch, t_pred, t_label, traintime, av_testtime = run(sess, x_train, y_train, x_test, y_test, args, case_str)
sess.close()
# save parameter settings and evaluated metrics
with open('modelselection'+case_str+'/evaluation.csv', 'a') as csv_file:
writer = csv.writer(csv_file)
writer.writerow(['noise', args.noise])
writer.writerow(['aug_num', args.n_aug])
writer.writerow(['n1', args.n1])
writer.writerow(['num_epochs', args.n_epochs])
writer.writerow(['batch_size', args.bs])
writer.writerow(['gamma', args.gamma])
writer.writerow(['loss', loss])
writer.writerow(['accuracy', accuracy])
writer.writerow(['epoch', epoch])
writer.writerow(['pred', t_pred])
writer.writerow(['label', t_label])
writer.writerow(['traintime', traintime])
writer.writerow(['average_testtime', av_testtime])