pytorch in 1 hour

.shape a tuple describing the dimensions #1 debugging tool .device where the tensor lives. cpu or cuda (GPU) .dtype the data type of the numbers. The default is float32 (because of backprop and gradients)

model weights and biases must be a float32 (standard) data that represents categories or counts can be integers

Autograd - Automatic Differentiation

  • it is python’s built in gradient calculator, and can be turned on using requires_grad=True
  • to tell pytorch a tensor is a learnable param we must set requires_grad=True, doing so pytorch tracks every single operation on that tensor!

The difference between * and @ in pytorch

  • for @ multiplication m1 col = m2 rows - used for neural networks

  • when building a linear layer always use @ y = X@W + b

Reduction - any operation that reduces a tensor to a smaller number of elements ex- sum(), mean(), max() etc.

dim arg

selecting data - basic and custom

making forward pass

  • model’s first guess
  • simple linear regression ŷ = XW + b The magic command - loss.backward()
    • calculates the gradient of the loss wrt to our weight “W”
    • the gradient of the loss wrt to our Bias ‘b’ for all the terms that are present in the autograd graph that pytorch has built!

gradient descent

torch.nn

  1. torch.nn.Linear

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