calculation of the perplexity score

[deven367]

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What is your question?

Why is the perplexity score calculated as (2**avg_nll_loss) instead of the regular exp(avg_nll_loss)

fairseq/fairseq_cli/eval_lm.py

Line 200 in bedb259

"perplexity": 2**avg_nll_loss,

Was this a deliberate choice made by the fairseq team? or is there some other reason behind it?

cc @b-dickson @zorant

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• fairseq Version (e.g., 1.0 or main): 0.12.2
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