[petsc-users] A number of questions about DMDA with SNES and Quasi-Newton methods

[zakaryah .]

Good point, Jed - I feel silly for missing this.

Can I use -snes_type test -snes_test_display with the Jacobian generated
from a DMComposite?  When I try, it looks like the finite difference
Jacobian is missing all the elements in the row corresponding to the
redundant variable, except the diagonal, which is wrong.

I'm not sure my code for setting the submatrices is correct.  I'm
especially uncertain about the submatrix J_bh, where b is the redundant
variable and h is the displacements.  This submatrix has only one row, and
all of its columns are non-zero.  Can its values be set with
MatSetValuesLocal, on all processors?

Is there an example of manually coding a Jacobian with a DMRedundant?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20171029/0136f6a5/attachment.html>