From ef678d2e1ba70b1a9dadb78c73ed372f986aea13 Mon Sep 17 00:00:00 2001 From: YurenHao0426 Date: Mon, 9 Feb 2026 12:28:55 -0600 Subject: Fix NLL double-shift bug and head weight init MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit - NLL loss was shifting labels twice (olmo_labels already shifted, then code did logits[:,:-1] vs labels[:,1:]). Fixed in 9 locations: trainer, pipeline, olmo_graph, sanity_check, eval. - Head U/V weights init with std=0.01 (was Kaiming ~5.7 std) so UV^T≈0 at init, ensuring Z≈logit_bias=15 and A≈0.953. - Updated SVD rank test to subtract logit_bias before checking. Co-Authored-By: Claude Opus 4.6 --- scripts/eval.py | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'scripts/eval.py') diff --git a/scripts/eval.py b/scripts/eval.py index bc471dc..33314cf 100644 --- a/scripts/eval.py +++ b/scripts/eval.py @@ -88,8 +88,8 @@ def main(): A_soft = predictor(raw_texts, tau=tau, mode="eval_soft") logits_soft = olmo_wrapper(olmo_ids, A_soft) nll_soft = F.cross_entropy( - logits_soft[:, :-1].contiguous().view(-1, vocab_size), - olmo_labels[:, 1:].contiguous().view(-1), + logits_soft.contiguous().view(-1, vocab_size), + olmo_labels.contiguous().view(-1), ) nll_soft_sum += nll_soft.item() @@ -97,8 +97,8 @@ def main(): A_hard = predictor(raw_texts, tau=tau, mode="eval_hard") logits_hard = olmo_wrapper(olmo_ids, A_hard) nll_hard = F.cross_entropy( - logits_hard[:, :-1].contiguous().view(-1, vocab_size), - olmo_labels[:, 1:].contiguous().view(-1), + logits_hard.contiguous().view(-1, vocab_size), + olmo_labels.contiguous().view(-1), ) nll_hard_sum += nll_hard.item() @@ -106,8 +106,8 @@ def main(): A_ones = create_all_ones_A(olmo_ids.shape[0]).to(device) logits_base = olmo_wrapper(olmo_ids, A_ones) nll_base = F.cross_entropy( - logits_base[:, :-1].contiguous().view(-1, vocab_size), - olmo_labels[:, 1:].contiguous().view(-1), + logits_base.contiguous().view(-1, vocab_size), + olmo_labels.contiguous().view(-1), ) nll_baseline_sum += nll_base.item() -- cgit v1.2.3