gentoo/dev-python/pyamg/files/pyamg-5.3.0-backport.patch
Michał Górny 519e0e715a
dev-python/pyamg: Backport upstream fix to make tests pass
Signed-off-by: Michał Górny <mgorny@gentoo.org>
2026-04-18 13:33:56 +02:00

37 lines
1.4 KiB
Diff

From 9f8299bcf1141e627503c3f208eda413bc1e28e6 Mon Sep 17 00:00:00 2001
From: Stephen Huan <stephen.huan@cgdct.moe>
Date: Tue, 24 Mar 2026 21:47:30 -0400
Subject: [PATCH] fix(util/utils): duplicate zeros in filter_operator
The explicit zeros added to A to match C's nonzeros can be redundant
with the existing entries in A. These duplicate entries are acted on
independently by amg_core.satisfy_constraints_helper, causing the
update to effectively happen multiple times when duplicate entries in
sparse arrays are added together according to scipy's semantics.
---
pyamg/util/utils.py | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/pyamg/util/utils.py b/pyamg/util/utils.py
index 69ed1507..4a955253 100644
--- a/pyamg/util/utils.py
+++ b/pyamg/util/utils.py
@@ -1242,7 +1242,7 @@ def filter_operator(A, C, B, Bf, BtBinv=None):
C = C.copy()
C.data[:] = 1
A = A.multiply(C)
- # add explicit zeros to A wherever C is nonzero, but A is zero
+ # add explicit zeros to A wherever C is nonzero
A = A.tocoo()
C = C.tocoo()
A.data = np.hstack((np.zeros(C.data.shape, dtype=A.dtype), A.data))
@@ -1252,6 +1252,8 @@ def filter_operator(A, C, B, Bf, BtBinv=None):
A = A.tobsr((rows_per_block, cols_per_block))
else:
A = A.tocsr()
+ # eliminate redundant zeros created by the above
+ A.sum_duplicates()
# Calculate difference between A @ B and Bf
diff = A @ B - Bf