freqtrade_origin/freqtrade/freqai/base_models/PyTorchModelTrainer.py
2023-03-06 20:15:36 +02:00

141 lines
4.7 KiB
Python

import logging
from pathlib import Path
from typing import Dict
from torch.optim import Optimizer
import torch
import torch.nn as nn
from torch.utils.data import DataLoader
from torch.utils.data import TensorDataset
import pandas as pd
logger = logging.getLogger(__name__)
class PyTorchModelTrainer:
def __init__(
self,
model: nn.Module,
optimizer: Optimizer,
criterion: nn.Module,
device: str,
batch_size: int,
max_iters: int,
eval_iters: int,
init_model: Dict
):
self.model = model
self.optimizer = optimizer
self.criterion = criterion
self.device = device
self.max_iters = max_iters
self.batch_size = batch_size
self.eval_iters = eval_iters
if init_model:
self.load_from_checkpoint(init_model)
def fit(self, data_dictionary: Dict[str, pd.DataFrame]):
data_loaders_dictionary = self.create_data_loaders_dictionary(data_dictionary)
epochs = self.calc_n_epochs(
n_obs=len(data_dictionary['train_features']),
batch_size=self.batch_size,
n_iters=self.max_iters
)
for epoch in range(epochs):
# evaluation
losses = self.estimate_loss(data_loaders_dictionary, data_dictionary)
logger.info(
f"epoch ({epoch}/{epochs}):"
f" train loss {losses['train']:.4f} ; test loss {losses['test']:.4f}"
)
# training
for batch_data in data_loaders_dictionary['train']:
xb, yb = batch_data
xb = xb.to(self.device)
yb = yb.to(self.device)
yb_pred = self.model(xb)
loss = self.criterion(yb_pred, yb)
self.optimizer.zero_grad(set_to_none=True)
loss.backward()
self.optimizer.step()
@torch.no_grad()
def estimate_loss(
self,
data_loader_dictionary: Dict[str, DataLoader],
data_dictionary: Dict[str, pd.DataFrame]
) -> Dict[str, float]:
self.model.eval()
epochs = self.calc_n_epochs(
n_obs=len(data_dictionary['test_features']),
batch_size=self.batch_size,
n_iters=self.eval_iters
)
loss_dictionary = {}
for split in ['train', 'test']:
losses = torch.zeros(epochs)
for i, batch in enumerate(data_loader_dictionary[split]):
xb, yb = batch
xb = xb.to(self.device)
yb = yb.to(self.device)
yb_pred = self.model(xb)
loss = self.criterion(yb_pred, yb)
losses[i] = loss.item()
loss_dictionary[split] = losses.mean().item()
self.model.train()
return loss_dictionary
def create_data_loaders_dictionary(
self,
data_dictionary: Dict[str, pd.DataFrame]
) -> Dict[str, DataLoader]:
data_loader_dictionary = {}
for split in ['train', 'test']:
labels_shape = data_dictionary[f'{split}_labels'].shape
labels_view = labels_shape[0] if labels_shape[1] == 1 else labels_shape
dataset = TensorDataset(
torch.from_numpy(data_dictionary[f'{split}_features'].values).float(),
torch.from_numpy(data_dictionary[f'{split}_labels'].astype(float).values)
.long()
.view(labels_view)
)
# todo currently assuming class labels are strings ['0.0', '1.0' .. n_classes].
# need to resolve it per ClassifierModel
data_loader = DataLoader(
dataset,
batch_size=self.batch_size,
shuffle=True,
drop_last=True,
num_workers=0,
)
data_loader_dictionary[split] = data_loader
return data_loader_dictionary
@staticmethod
def calc_n_epochs(n_obs: int, batch_size: int, n_iters: int) -> int:
n_batches = n_obs // batch_size
epochs = n_iters // n_batches
return epochs
def save(self, path: Path):
torch.save({
'model_state_dict': self.model.state_dict(),
'optimizer_state_dict': self.optimizer.state_dict(),
}, path)
def load_from_file(self, path: Path):
checkpoint = torch.load(path)
return self.load_from_checkpoint(checkpoint)
def load_from_checkpoint(self, checkpoint: Dict):
self.model.load_state_dict(checkpoint['model_state_dict'])
self.optimizer.load_state_dict(checkpoint['optimizer_state_dict'])
return self