Specific input to sparse QR solve produces erroneous result
Submitted by Jeff Trull
Assigned to Nobody
Link to original bugzilla bug (#1563)
Version: 3.3 (current stable)
Description
Created attachment 864
minimal test case
While running sparseqr_1 I stumbled across a (literally) one in a million bug. This input matrix:
[ 10.875, 0, 0, 0, 0;
-0.397597, 12.1403, 0, 0, 0.0317254;
-0.851737, -0.0269339, 11.3113, 0.0130592, 0;
-0.676106, 0, 0.138752, 8.57745, 0]
when factored and solved for:
[ 10.3612;
-2.27836;
-10.3179;
-7.49344]
produces dramatically different results between dense and sparse implementations.
Attachment 864, "minimal test case":
repro.cpp
Edited by Eigen Bugzilla