Any example of assembling a Jacobian matrix of DMComposite object?

[(Rebecca) Xuefei YUAN]

Hi,

I have an optimization problem in 2d with some scalar parameter, thus  
DMComposite is used to manage the date structure. If I am going to  
write down the Jacobian matrix for the system, I come up with  
(mx*my+1,mx*my+1) matrix. Is there any example in PETSc of assembling  
the Jacobian for optimization problem?

Thanks very much!

-- 
(Rebecca) Xuefei YUAN
Department of Applied Physics and Applied Mathematics
Columbia University
Tel:917-399-8032
www.columbia.edu/~xy2102