Python Lightning for sine wave simulation - neural-network

Question

I am getting an error when i run the below code. The error says
MisconfigurationException: No training_step() method defined. Lightning Trainer expects as minimum a training_step(), train_dataloader() and configure_optimizers() to be defined.
Can someone please let me know what is the issue here? I am very new to Pytorch. I am trying to simulate Sin wave using MLP
import numpy as np ## using again numpy library for Sin function
import torch ## using pytorch
import matplotlib.pyplot as plt
import pytorch_lightning as pl
import torch.optim as optim
from torch import nn
from pytorch_lightning import Trainer
from sklearn.model_selection import train_test_split
import pandas as pd
from torch.utils.data import DataLoader
N=1000 ## 1000 samples to be generated
L=1000 ## length of each sample
T=20 ## width of wave
x = np.random.randn(1000)
y = np.sin(x)
df = pd.DataFrame({'x':x, 'y':y})
train, test = train_test_split(df, test_size=0.2, random_state=42, shuffle=True)
target_fields=['y']
train_features, train_targets = train.drop(target_fields, axis=1), train[target_fields]
test_features, test_targets = test.drop(target_fields, axis=1), test[target_fields]
class MLP(pl.LightningModule):
def __init__(self):
super(MLP,self).__init__()
self.fc1 = nn.Linear(1, 10)
self.fc2 = nn.Linear(10, 1)
def forward(self, x):
x = torch.Relu(self.fc1(x))
x = self.fc2(x)
return x
l_rate = 0.2
mse_loss = nn.MSELoss(reduction = 'mean')
def train_dataloader(self):
train_dataset = TensorDataset(torch.tensor(train_features.values).float(), torch.tensor(train_targets[['cnt']].values).float())
train_loader = DataLoader(dataset = train_dataset, batch_size = 128)
return train_loader
def test_dataloader(self):
test_dataset = TensorDataset(torch.tensor(test_features.values).float(), torch.tensor(test_targets[['cnt']].values).float())
test_loader = DataLoader(dataset = test_dataset, batch_size = 128)
return test_loader
def configure_optimizers(self):
return optim.SGD(self.parameters(), lr=l_rate)
def training_step(self, batch, batch_idx):
x, y = batch
logits = self.forward(x)
loss = mse_loss(logits, y)
# Add logging
logs = {'loss': loss}
return {'loss': loss, 'log': logs}
def test_step(self, batch, batch_idx):
x, y = batch
logits = self.forward(x)
loss = mse_loss(logits, y)
correct = torch.sum(logits == y.data)
predictions_pred.append(logits)
predictions_actual.append(y.data)
return {'test_loss': loss, 'test_correct': correct, 'logits': logits}
def test_epoch_end(self, outputs):
avg_loss = torch.stack([x['test_loss'] for x in outputs]).mean()
logs = {'test_loss': avg_loss}
return {'avg_test_loss': avg_loss, 'log': logs, 'progress_bar': logs }
model = MLP()
trainer = Trainer(max_epochs = 50)
trainer.fit(model)
Error
GPU available: False, used: False
TPU available: False, using: 0 TPU cores
IPU available: False, using: 0 IPUs
---------------------------------------------------------------------------
MisconfigurationException Traceback (most recent call last)
<ipython-input-9-7bdf5ac9771f> in <module>()
1 model = MLP()
2 trainer = Trainer(max_epochs = 50)
----> 3 trainer.fit(model)
3 frames
/usr/local/lib/python3.7/dist-packages/pytorch_lightning/trainer/configuration_validator.py in __verify_train_loop_configuration(self, model)
50 if not has_training_step:
51 raise MisconfigurationException(
---> 52 "No `training_step()` method defined. Lightning `Trainer` expects as minimum a"
53 " `training_step()`, `train_dataloader()` and `configure_optimizers()` to be defined."
54 )
MisconfigurationException: No `training_step()` method defined. Lightning `Trainer` expects as minimum a `training_step()`, `train_dataloader()` and `configure_optimizers()` to be defined.

Answer 1

You are missing 2 parameters in your trainer.fit() call. See the documentation