example.py

"""
@author: hitlic
"""
from deepepochs import Trainer, rename, CheckCallback, EpochTask, LogCallback
import torch
from torch import nn
from torch.nn import functional as F
from torchvision.datasets import MNIST
from torchvision import transforms
from torch.utils.data import DataLoader, random_split
from torchmetrics import functional as MF

import random
import numpy as np
torch.manual_seed(1)
np.random.seed(1)
random.seed(1)

# datasets
data_dir = './datasets'
transform = transforms.Compose([transforms.ToTensor(), transforms.Normalize((0.1307,), (0.3081,))])
mnist_full = MNIST(data_dir, train=True, transform=transform, download=True)
train_ds, val_ds, _ = random_split(mnist_full, [5000, 5000, 50000])
test_ds = MNIST(data_dir, train=False, transform=transform, download=True)

# dataloaders
train_dl = DataLoader(train_ds, batch_size=32)
val_dl = DataLoader(val_ds, batch_size=32)
test_dl = DataLoader(test_ds, batch_size=32)

# pytorch model
channels, width, height = (1, 28, 28)
model = nn.Sequential(
    nn.Flatten(),
    nn.Linear(channels * width * height, 64),
    nn.ReLU(),
    nn.Dropout(0.1),
    nn.Linear(64, 64),
    nn.ReLU(),
    nn.Dropout(0.1),
    nn.Linear(64, 10)
)

def acc(preds, targets):
    return MF.accuracy(preds, targets, task='multiclass', num_classes=10)

@rename('')
def multi_metrics(preds, targets):
    return {
        'p': MF.precision(preds, targets, task='multiclass', num_classes=10),
        'r': MF.recall(preds, targets, task='multiclass', num_classes=10)
        }


checker = CheckCallback('loss', on_stage='val', mode='min', patience=2)
logger = LogCallback()
opt = torch.optim.Adam(model.parameters(), lr=2e-4)

trainer = Trainer(model, F.cross_entropy, opt=opt, epochs=6,
                  callbacks=[checker, logger], metrics=[acc], log_long=False)

# 应用示例1：
progress = trainer.fit(train_dl, val_dl, metrics=[multi_metrics], val_freq=2)
test_rst = trainer.test(test_dl)


# 应用示例2：
# t1 = EpochTask(train_dl, metrics=[acc])
# t2 = EpochTask(val_dl, metrics=[multi_metrics], do_loss=True)
# progress = trainer.fit(train_tasks=[t1,t2], val_tasks=[t1, t2])
# test_rst = trainer.test(tasks=t2)

# 应用示例3：
# t1 = EpochTask(train_dl, metrics=[acc])
# t2 = EpochTask(val_dl, metrics=[acc, multi_metrics], do_loss=True)
# progress = trainer.fit(train_dl, val_tasks=[t1, t2])
# test_rst = trainer.test(tasks=[t1, t2])