import torch import math dtype = torch.float device = torch.device("cpu")
# Create random input and output data x = torch.linspace(-math.pi, math.pi, 2000, device=device, dtype=dtype) y = torch.sin(x)
# Randomly initialize weights a = torch.randn((), device=device, dtype=dtype) b = torch.randn((), device=device, dtype=dtype) c = torch.randn((), device=device, dtype=dtype) d = torch.randn((), device=device, dtype=dtype)
learning_rate = 1e-6 for t inrange(2000): # Forward pass: compute predicted y y_pred = a + b * x + c * x ** 2 + d * x ** 3 # Compute and print loss loss = (y_pred - y).pow(2).sum().item() if t % 100 == 99: print(t, loss) # Backprop to compute gradients of a, b, c, d with respect to loss grad_y_pred = 2.0 * (y_pred - y) grad_a = grad_y_pred.sum() grad_b = (grad_y_pred * x).sum() grad_c = (grad_y_pred * x ** 2).sum() grad_d = (grad_y_pred * x ** 3).sum() # Update weights using gradient descent a -= learning_rate * grad_a b -= learning_rate * grad_b c -= learning_rate * grad_c d -= learning_rate * grad_d print(f'Result: y = {a.item()} + {b.item()} x + {c.item()} x^2 + {d.item()} x^3')
在 Activity Monitor 上检查,其确实在 Apple 上运行,非 Intel
torchvision
安装 torchvision,注意版本,直接 conda安装默认的最新版本会出错
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>>> print(torch.__version__) 1.11.0
有建议安装 0.9 版本,确实是能成功安装的,但是 load MNIST dataset 会报错。
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conda install torchvision==0.9
urllib.error.HTTPError: HTTP Error 502: Bad Gatewayfor downloading MNIST dataset
TensorFlow installation not found - running with reduced feature set. Serving TensorBoard on localhost; to expose to the network, use a proxy or pass --bind_all TensorBoard 2.8.0 at http://localhost:6006/ (Press CTRL+C to quit)