find_dupes: fix uint64 hamming accumulation (numpy casts to float64)

2026-10-18 18:42:51 -04:00
parent a8cf8957d5
commit 4816b007c0
1 changed files with 4 additions and 3 deletions
@@ -93,9 +93,10 @@ def main():
    n = len(names)
    print(f"Pairwise compare {n}x{n} (numpy hamming) ...")
    dmat = np.array([data[f][0] for f in names], dtype=np.uint64)
-    # hamming distances via xor + popcount
-    x = dmat[:, None] ^ dmat[None, :]
-    ham = np.zeros_like(x)
+    # hamming distances via xor + popcount (work in int64; numpy has no
+    # sane uint64 shift-add promotion)
+    x = (dmat[:, None] ^ dmat[None, :]).astype(np.int64)
+    ham = np.zeros(x.shape, dtype=np.int16)
    for b in range(64):
        ham += ((x >> b) & 1).astype(np.int16)