[petsc-users] Bug Report TaoALMM class

[Stephan Köhler]

Dear PETSc/Tao team,

I think there might be a bug in the Tao ALMM class:  In the function
TaoALMMComputeAugLagAndGradient_Private(), see, eg. 
https://petsc.org/release/src/tao/constrained/impls/almm/almm.c.html#TAOALMM 
line 648 the gradient seems to be wrong.

The given function and gradient computation is
Lc = F + Ye^TCe + Yi^T(Ci - S) + 0.5*mu*[Ce^TCe + (Ci - S)^T(Ci - S)],
dLc/dX = dF/dX + Ye^TAe + Yi^TAi + 0.5*mu*[Ce^TAe + (Ci - S)^TAi],

but I think the gradient should be (without 0.5)

dLc/dX = dF/dX + Ye^TAe + Yi^TAi + mu*[Ce^TAe + (Ci - S)^TAi].

Kind regards,
Stephan Köhler

-- 
Stephan Köhler
TU Bergakademie Freiberg
Institut für numerische Mathematik und Optimierung

Akademiestraße 6
09599 Freiberg
Gebäudeteil Mittelbau, Zimmer 2.07

Telefon: +49 (0)3731 39-3173 (Büro)

-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_0xC9BF2C20DFE9F713.asc
Type: application/pgp-keys
Size: 758 bytes
Desc: OpenPGP public key
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20230612/ef99e495/attachment.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_signature
Type: application/pgp-signature
Size: 236 bytes
Desc: OpenPGP digital signature
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20230612/ef99e495/attachment.sig>