[Coin-ipopt] (no subject)

[Nguyen An Danh]

Hi Andreas,

Thank you very much for your very long email.  Your advice is very helpful for 
me.  My problem has run after  I changed a new starting point.  I hope that I 
could have its solution soon.

Could you explain me the following questions?

1.  Since with the problem of 112001 variables, ma27_call:  LA increased from    
66993497 to   279769007,  I doubt that another problem of mine which has over 
millions variables will meet difficulty with MA27. (I wish that it would not 
happen!!!) .  So I start to learn how to change MA27 to PARDISO .
If I did so, what would be advantages and disavantages?  I know that changing 
linear solver has much works.
What is the disadvantage of PARDISO (Fortran version) on http://
www.computational.unibas.ch/cs/scicomp/software/pardiso/ ?

2.  Since the mechanical properties of my model, I intend  to add a mechanical 
law  for variables when Ipopt solves equation (9) in your paper "On the 
Implementation of an Interior PointFilter..." .  It means that after Ipopt 
has calculated x(k) at step k, I shall modify x(k) for the next step k+1.  If 
I did so, what should I mention to keep searching direction?  Is it possible 
in optimisation?  Could it make my problem becomes concave?

Thank you so much in advance.