-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 21/10/15 14:14, Anna Kalogirou wrote:
Dear Lawrence,
I believe the code (attached) sets up the matrices/vectrors/operators correctly. However, I have one question: Due to the use of a heavyside function, the operator B on the LHS is nonzero in a block NxN, say, in the bottom right corner. For that reason, when I solved the linear system in Matlab I only considered these nonzero values in the block, because otherwise the LHS would not be invertible. How come and it doesn't complain here?
So it's clear that the matrix C = Q1*Q2^T is not invertible, however, presumably you're solving for: B = A + C where A is full rank and invertible. So I don't immediately see why there would be a problem in trying to invert B which is what the solver does. Lawrence -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQEcBAEBAgAGBQJWJ5KFAAoJECOc1kQ8PEYv7F8IANoAlaJs8bPi72Hi/YdveiG+ y02EBN/gzM8JQtJAV/4IPyldt//koM4BEp6BAUG0T4GlZrXPoJY8wz9lG9SJnVer XARcV8C7EmQV5uW9vgK2pGMbt7ZHrIEClVZCAaGYT/rmP+l0XKolMxDXH7tKipIq enjIEoS1mrvVj2iSj58T3NZLM3547r9ChrdS/+Mdkn15rXoR2KS0bapEHITkVppi 6qFSU8OVRbcx/HA8GypX7K2ya1X3MTSwmBhdTO0SAdsOnTgPPBb11y9ziQ3onWPw hqaGpasc3ACSB06VDisGlkZYFNg/iS3nbF3mIsqP/2+8VPaoyxkQmnngKLgGegw= =0uCV -----END PGP SIGNATURE-----