如何在 Microsoft Fabric 中使用 PyTorch 定型模型
PyTorch 機器學習架構是以 Torch 連結庫為基礎。 PyTorch 通常用於電腦視覺和自然語言處理應用程式。 本文提供如何定型和追蹤 PyTorch 模型的反覆專案範例。
安裝 PyTorch
若要開始使用 PyTorch,您必須確認其已安裝在筆記本中。 您可以使用下列命令在您的環境中安裝或升級 PyTorch 版本:
%pip install torch
設定機器學習實驗
使用 MLFLow API 建立機器學習實驗。 如果 MLflow set_experiment() API 不存在,就會建立新的機器學習實驗。
import mlflow
mlflow.set_experiment("sample-pytorch")
定型和評估 Pytorch 模型
建立實驗之後,下一個程式代碼範例會載入 MNSIT 數據集、產生我們的測試和定型數據集,並建立定型函式。
import os
import torch
import torch.nn as nn
from torch.autograd import Variable
import torchvision.datasets as dset
import torchvision.transforms as transforms
import torch.nn.functional as F
import torch.optim as optim
## load mnist dataset
root = "/tmp/mnist"
if not os.path.exists(root):
os.mkdir(root)
trans = transforms.Compose(
[transforms.ToTensor(), transforms.Normalize((0.5,), (1.0,))]
)
# if not exist, download mnist dataset
train_set = dset.MNIST(root=root, train=True, transform=trans, download=True)
test_set = dset.MNIST(root=root, train=False, transform=trans, download=True)
batch_size = 100
train_loader = torch.utils.data.DataLoader(
dataset=train_set, batch_size=batch_size, shuffle=True
)
test_loader = torch.utils.data.DataLoader(
dataset=test_set, batch_size=batch_size, shuffle=False
)
print("==>>> total trainning batch number: {}".format(len(train_loader)))
print("==>>> total testing batch number: {}".format(len(test_loader)))
## network
class LeNet(nn.Module):
def __init__(self):
super(LeNet, self).__init__()
self.conv1 = nn.Conv2d(1, 20, 5, 1)
self.conv2 = nn.Conv2d(20, 50, 5, 1)
self.fc1 = nn.Linear(4 * 4 * 50, 500)
self.fc2 = nn.Linear(500, 10)
def forward(self, x):
x = F.relu(self.conv1(x))
x = F.max_pool2d(x, 2, 2)
x = F.relu(self.conv2(x))
x = F.max_pool2d(x, 2, 2)
x = x.view(-1, 4 * 4 * 50)
x = F.relu(self.fc1(x))
x = self.fc2(x)
return x
def name(self):
return "LeNet"
## training
model = LeNet()
optimizer = optim.SGD(model.parameters(), lr=0.01, momentum=0.9)
criterion = nn.CrossEntropyLoss()
for epoch in range(1):
# trainning
ave_loss = 0
for batch_idx, (x, target) in enumerate(train_loader):
optimizer.zero_grad()
x, target = Variable(x), Variable(target)
out = model(x)
loss = criterion(out, target)
ave_loss = (ave_loss * batch_idx + loss.item()) / (batch_idx + 1)
loss.backward()
optimizer.step()
if (batch_idx + 1) % 100 == 0 or (batch_idx + 1) == len(train_loader):
print(
"==>>> epoch: {}, batch index: {}, train loss: {:.6f}".format(
epoch, batch_idx + 1, ave_loss
)
)
# testing
correct_cnt, total_cnt, ave_loss = 0, 0, 0
for batch_idx, (x, target) in enumerate(test_loader):
x, target = Variable(x, volatile=True), Variable(target, volatile=True)
out = model(x)
loss = criterion(out, target)
_, pred_label = torch.max(out.data, 1)
total_cnt += x.data.size()[0]
correct_cnt += (pred_label == target.data).sum()
ave_loss = (ave_loss * batch_idx + loss.item()) / (batch_idx + 1)
if (batch_idx + 1) % 100 == 0 or (batch_idx + 1) == len(test_loader):
print(
"==>>> epoch: {}, batch index: {}, test loss: {:.6f}, acc: {:.3f}".format(
epoch, batch_idx + 1, ave_loss, correct_cnt * 1.0 / total_cnt
)
)
torch.save(model.state_dict(), model.name())
使用 MLflow 的記錄模型
現在,您會啟動 MLflow 執行,並追蹤我們的機器學習實驗內的結果。
with mlflow.start_run() as run:
print("log pytorch model:")
mlflow.pytorch.log_model(
model, "pytorch-model", registered_model_name="sample-pytorch"
)
model_uri = "runs:/{}/pytorch-model".format(run.info.run_id)
print("Model saved in run %s" % run.info.run_id)
print(f"Model URI: {model_uri}")
此程式代碼會使用指定的參數建立回合,並在 sample-pytorch 實驗中記錄執行。 代碼段會建立名為 sample-pytorch 的新模型。
載入和評估模型
儲存模型之後,也可以載入以進行推斷。
# Inference with loading the logged model
loaded_model = mlflow.pytorch.load_model(model_uri)
print(type(loaded_model))
correct_cnt, total_cnt, ave_loss = 0, 0, 0
for batch_idx, (x, target) in enumerate(test_loader):
x, target = Variable(x, volatile=True), Variable(target, volatile=True)
out = loaded_model(x)
loss = criterion(out, target)
_, pred_label = torch.max(out.data, 1)
total_cnt += x.data.size()[0]
correct_cnt += (pred_label == target.data).sum()
ave_loss = (ave_loss * batch_idx + loss.item()) / (batch_idx + 1)
if (batch_idx + 1) % 100 == 0 or (batch_idx + 1) == len(test_loader):
print(
"==>>> epoch: {}, batch index: {}, test loss: {:.6f}, acc: {:.3f}".format(
epoch, batch_idx + 1, ave_loss, correct_cnt * 1.0 / total_cnt
)
)
相關內容
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