Skip to content

Instantly share code, notes, and snippets.

@leopd
Last active April 21, 2023 22:35
Show Gist options
  • Star 11 You must be signed in to star a gist
  • Fork 0 You must be signed in to fork a gist
  • Save leopd/29786dd4a2a8ba801324b77fee7f4348 to your computer and use it in GitHub Desktop.
Save leopd/29786dd4a2a8ba801324b77fee7f4348 to your computer and use it in GitHub Desktop.
Explanatory (non-vectorized) code for how attention works
# This code doesn't work, and isn't intended to.
# The goal of this code is to explain how attention mechansisms work, in code.
# It is deliberately not vectorized to make it clearer.
def attention(self, X_in:List[Tensor]):
# For every token transform previous layer's out
for i in range(self.sequence_length):
query[i] = self.Q * X_in[i]
key[i] = self.K * X_in[i]
value[i] = self.V * X_in[i]
# Compute output values, one at a time
for i in range(self.sequence_length):
this_query = query[i]
# how relevant is each input to this out?
for j in range(self.sequence_length):
relevance[j] = this_query * key[j]
# normalize relevance scores to sum to 1
relevance = scaled_softmax(relevance)
# compute a weighted sum of the values
out[i] = 0
for j in range(self.sequence_length):
out[i] += relevance[j] * value[j]
return out
@Sandy4321
Copy link

Hello Leo,

This code doesn't work, and isn't intended to.

great repo and talk
https://www.youtube.com/watch?v=S27pHKBEp30&t=382s
LSTM is dead. Long Live Transformers!
only can you share link to your or somebody else working plain only numpy python code to learn this new ideas.
Meaning full example from 0 to end with data input file and expected output example

Thank you very much on advance

@banderlog
Copy link

Q,K,V are matrices to be learned.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment