How can I avoid underfitting in Pytorch NeuralNetwork - machine-learning

Question

How can I avoid underfitting in Pytorch NeuralNetwork?
I try to predict the power consumtion of a plant based on seven features. I have built two simple neural network models.
The first one is a Linear model, and the second is a RNN model. However, both models perform bad in the test set, their forecast result is a straight line.
Something about data
There are about 360 samples in the CSV file. I take the first 300 samples for trainning and the others for test. The first 7 columns of raw data are features of daily operation. The last column is the electricity consumption of every day.
Setting of training set
In the linear model, train data is the first 7 colums of a certain day, and corresponding target is the power consumption of that day.
In the RNN model, train data is all the 8 columns of three days(seven features and power consumption), and corresponding traget is the power consumption of next three days.
Code
Code of RNN model
import torch
import pandas as pd
import numpy as np
import torch.nn.functional as f
import torch.optim as optim
from torch.utils.data import DataLoader, TensorDataset
from matplotlib import pyplot as plt
'''
build simple RNN
'''
batchSize = 3
device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
netPath = ''
'''Data processing'''
# read raw data
filePath = 'F:/.csv'
initialData = pd.read_csv(filePath)
print(initialData.head(10))
print('hello world')
# Separate features and power consumption.
trainDatas = initialData.iloc[0:7, 1:301]
trainPowerConsum = pd.DataFrame(initialData.iloc[-1, 1:301]).T
trainDatas = pd.concat([trainDatas, trainPowerConsum], 0)
trainPowerConsum = initialData.iloc[-1, 2:302]
# Plot
powerConsumPlot = trainDatas.iloc[-1, :]
xData = np.linspace(1, powerConsumPlot.shape[0], 300)
plt.plot(xData, powerConsumPlot)
plt.show()
testDatas = initialData.iloc[0:7, 302:-1]
testPowerConsum = pd.DataFrame(initialData.iloc[-1, 302:-1]).T
testDatas = pd.concat([testDatas, testPowerConsum], 0)
testPowerConsum = initialData.iloc[-1, 303:]
# convert to dataframe
trainDatas = pd.DataFrame(trainDatas)
trainDatas = trainDatas.T
trainPowerConsum = pd.DataFrame(trainPowerConsum)
testDatas = pd.DataFrame(testDatas)
testDatas = testDatas.T
testPowerConsum = pd.DataFrame(testPowerConsum)
# change the unit of PowerConsumption
trainDatas.iloc[:, -1] = trainDatas.iloc[:, -1] * 1000
testDatas.iloc[:, -1] = testDatas.iloc[:, -1] * 1000
trainPowerConsum.iloc[:, 0] = trainPowerConsum.iloc[:, 0] * 1000
testPowerConsum.iloc[:, 0] = testPowerConsum.iloc[:, 0] * 1000
assert testPowerConsum.shape[0] == testDatas.shape[0]
assert trainDatas.shape[0] == trainPowerConsum.shape[0]
# convert dataframe to tensor
trainDatas = torch.tensor(trainDatas.values.astype(float), device=device)
trainPowerConsum = torch.tensor(trainPowerConsum.values.astype(float), device=device)
testDatas = torch.tensor(testDatas.values.astype(float), device=device)
testPowerConsum = torch.tensor(testPowerConsum.values.astype(float), device=device)
trainDatasList = list()
trainPowerConsumList = list()
for i in range(298):
trainDatasList.append(trainDatas[i:i + 3])
trainPowerConsumList.append(trainPowerConsum[i:i + 3])
from torch.nn.utils.rnn import pad_sequence
trainPowerConsum = pad_sequence(trainPowerConsumList, batch_first=True)
trainDatas = pad_sequence(trainDatasList, batch_first=True)
print(trainDatas.shape)
# ensure the batch_size of test data is 1
testDatas = torch.unsqueeze(testDatas, dim=0)
testPowerConsum = torch.unsqueeze(testPowerConsum, dim=0)
'''build dataloader'''
trainDataLoader = DataLoader(
TensorDataset(
trainDatas, trainPowerConsum
),
shuffle=True, batch_size=batchSize, drop_last=True)
print('Data is ready')
seqLen = 2
inputDim = 8
hiddenSize = 3
numLayer = 2
learningRate = 0.01
class RNNModel(torch.nn.Module):
def __init__(self, inputsize, hiddensize, batchsize, numLayer):
super(RNNModel, self).__init__()
self.batchsize = batchsize
self.inputsize = inputsize
self.hiddensize = hiddensize
self.numlayers = numLayer
self.rnn = torch.nn.RNN(input_size=self.inputsize, hidden_size=self.hiddensize, num_layers=self.numlayers,
batch_first=True)
self.l1 = torch.nn.Linear(hiddenSize, hiddensize)
self.l2 = torch.nn.Linear(hiddenSize, 1)
def forward(self, input, hidden):
out, hidden = self.rnn(input.float(), hidden.float())
batch_size, seq_len, input_dim = out.shape
out = out.reshape(-1, input_dim)
# out = f.sigmoid(self.l1(out))
out = f.relu(self.l1(out))
out = self.l2(out)
out = out.reshape(batch_size, seq_len, -1)
return out, hidden
def initHidden(self):
hidden = torch.zeros(self.numlayers, self.batchsize, self.hiddensize, device=device, dtype=torch.float64)
return hidden
net = RNNModel(inputDim, hiddenSize, batchSize, numLayer).to(device)
criterion = torch.nn.L1Loss()
optimizer = optim.Adam(net.parameters(), lr=learningRate,momentum=0.01)
def train(epoch):
runLoss = 0.
optimizer.zero_grad()
hidden = net.initHidden()
for batchIndex, data in enumerate(trainDataLoader, 0):
inputs, target = data
optimizer.zero_grad()
outputs, hidden = net(inputs, hidden)
hidden = hidden.detach()
loss = criterion(outputs.float(), target.float())
loss = loss.mean()
loss.backward()
optimizer.step()
print(f'{epoch + 1},\t Loss={loss.item()}')
# torch.save(net.state_dict(), netPath)
def test():
testDatasVice = torch.clone(testDatas)
input = testDatasVice[:, 0, :]
input = input.view(1, 1, -1)
assert input.shape[2] == 8
predictPowConsum = list()
# the first hidden tensor in test set is zero
hidden = torch.zeros(2, 1, 3, device=device, dtype=torch.float64)
with torch.no_grad():
for i in range(testDatas.shape[1]):
output, hidden = net(input, hidden)
if i < 51:
testDatasVice[:, i + 1, -1] = output[0]
input = torch.unsqueeze(testDatasVice[:, i + 1, :], dim=0)
predictPowConsum.append(output.data.cpu().numpy().ravel()[0])
elif i == 51:
predictPowConsum.append(output.data.cpu().numpy().ravel()[0])
else:
print('\tindexError') # Exclude potential Errors
return predictPowConsum
if __name__ == '__main__':
epochNum = 300
for epoch in range(epochNum):
train(epoch)
predictPowConsum = test()
# plotting
xData = np.arange(303, 303 + testPowerConsum.size(1))
plt.plot(xData, testPowerConsum.cpu().numpy()[0, :, 0])
plt.plot(xData, predictPowConsum)
plt.show()
Code of Linear model
import torch
import pandas as pd
import numpy as np
import torch.nn.functional as f
import torch.optim as optim
from torch.utils.data import DataLoader, TensorDataset
from matplotlib import pyplot as plt
filePath = 'F:.csv'
initialData = pd.read_csv(filePath)
print(initialData.head(10))
print('hello world')
trainDatas = initialData.iloc[0:7, 1:300]
trainPowerConsum = initialData.iloc[-1, 1:300]
testDatas = initialData.iloc[0:7, 300:-1]
testPowerConsum = initialData.iloc[-1, 300:-1]
trainDatas = pd.DataFrame(trainDatas)
trainDatas = trainDatas.T
trainPowerConsum = pd.DataFrame(trainPowerConsum)
testDatas = pd.DataFrame(testDatas)
testDatas = testDatas.T
testPowerConsum = pd.DataFrame(testPowerConsum)
trainPowerConsum.iloc[:, 0] = trainPowerConsum.iloc[:, 0] * 1000
testPowerConsum.iloc[:, 0] = testPowerConsum.iloc[:, 0] * 1000
# build dataloader
trainData = DataLoader(
TensorDataset(
torch.tensor(trainDatas.values).float(),
torch.tensor(trainPowerConsum.values.astype(float)).float()
),
shuffle=True, batch_size=15)
testData = DataLoader(
TensorDataset(
torch.tensor(testDatas.values.astype(float)).float(),
torch.tensor(testPowerConsum.values.astype(float)).float()
),
shuffle=False, batch_size=15)
print('data is ready')
class SimpleNet(torch.nn.Module):
def __init__(self):
super(SimpleNet, self).__init__()
self.l1 = torch.nn.Linear(7, 15)
self.l2 = torch.nn.Linear(15, 30)
self.l3 = torch.nn.Linear(30, 15)
self.l4 = torch.nn.Linear(15, 5)
self.l5 = torch.nn.Linear(5, 1)
def forward(self, x):
x = f.relu(self.l1(x))
x = f.relu(self.l2(x))
x = f.relu(self.l3(x))
x = f.relu(self.l4(x))
return self.l5(x)
model = SimpleNet()
criterion = torch.nn.MSELoss()
optimizer = optim.SGD(model.parameters(), lr=0.0001)
def train(epoch):
runLoss = 0.
for batch_index, data in enumerate(trainData, 0):
inputs, target = data
optimizer.zero_grad()
outputs = model(inputs)
loss = criterion(outputs, target)
loss.backward()
optimizer.step()
runLoss += loss
print(f'{epoch + 1},{batch_index + 1},\tLoss={runLoss / 5}')
runLoss = 0
def test(epoch):
totalError = 0.
print('Start to test the model')
with torch.no_grad():
for data in testData:
# test ---------data for test
# testlab ---------corresponding power consumption
test, testlab = data
outputs = model(test)
predicted = outputs.data
testError = testlab - predicted
# plotting
if epoch % 50 == 2:
xData = np.linspace(1, 15, 15)
if predicted.size(0) != 15:
pass
else:
plt.plot(xData, predicted[:, 0].numpy(), label='predicted', color='red')
plt.plot(xData, testlab[:, 0].numpy(), label='origData', color='blue')
plt.show()
totalError += (torch.abs(testError).sum().item())
print(f'Average Error on test set is {totalError / 54}')
if __name__ == '__main__':
for epoch in range(1000):
train(epoch)
test(epoch)
Image of Output
output of RNN
The blue line is the actual data, and the orange line is the output of RNN model.
Solutions and its Effect
I have looked around and apparently I've got the choice between these solutions:
Add new domain-specific features
Decrease the amount of regularization used
Increase the duration of training
Increase the complexity or type of the model
Decrease the learning rate
Try other activate function
I have tried some solutions:
The data for trainning isn't regularized. I just change the unit of electricity from kWh to Wh
I take ReLu as activate function after using Sigmoid, but it doesn't work
I adjust the learning rate from 0.01 to 0.001, it doesn't improve
I try different optimizer such as SGD and Adam on both model, even use momentum, it doesn't get better
The sequence length of RNN model is 60 firstly, then is set to 3. The loss dropped more rapidly in the latter case, but the forecast result still is a straight line
In a word, all solutions I find doesn't work.
Besides, if shuffle is True when building DataLoader, the loss skips violently between epochs. But it drops slowly and close to an constant eventually when shuffle is False.
What could be the best way to avoid the problem?
Thanks in advance!