[Ipopt] Size of the KKT matrix

Senses,Begum bgmsenses at ufl.edu
Fri Aug 30 16:44:45 EDT 2013

Hello everyone,

I want to get the KKT matrix from Ipopt at every iteration. Therefore I 
set Ipopt print level to 12. As expected, Ipopt prints out the KKT 
matrix. The unexpected thing is the size of the KKT matrix. When I 
construct the KKT matrix  from the hessian and the jacobian, which I 
give to IPOPT at the beginning, it has a size 448 x 448. However, the 
size of the KKT matrix that Ipopt prints is 442 x 442. Does this mean 
the KKT matrix is rank deficient or is there anything else going on in 
the Ipopt that changes the size of the KKT matrix.


Senses, Begum

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