pytorch shape_error ai_generated true

RuntimeError: The size of tensor a must match the size of tensor b

ID: pytorch/broadcast-shape-mismatch

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85%Fix Rate
88%Confidence
3Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
2 active — — —

Root Cause

Tensor shapes incompatible for broadcasting.

generic

Workarounds

  1. 92% success Check tensor shapes with .shape and use .unsqueeze() or .view() correctly
  2. 88% success Use torch.broadcast_shapes() to verify compatibility first

Dead Ends

Common approaches that don't work:

  1. Reshape one tensor arbitrarily 82% fail

    Wrong semantics, silent data corruption

  2. Use expand on both tensors to max size 75% fail

    Memory waste, same error if dims wrong