Sir So where does these functions obtain x and where does the hess function obtain lambda from? Because when I define these functions and I provide X and lambda as inputs, it'll show error, I thought.
Regards Viswanath On Oct 19, 2017 10:47 AM, "Ray Zimmerman" <[email protected]> wrote: > Hi Viswanath, > > Since your constraint is an inequality, let’s call it h(x). And since, > h(x) <= 0, you need to define it as … > > h(x) = x'Hx + e'x + C – N > > 1. The function you need to implement computes the Hessian of lambda’ * > h(x) for a given value of lambda and x. Both lambda and x are provided as > inputs, you provide the Hessian of lambda’ * h(x) as output. Since h(x) > (and also lambda) is a scalar in your case, the Hessian is simply lambda * > H. > > 2. I assume N is a constant that is entered as part of your definition of > h(x). > > Ray > > > On Oct 18, 2017, at 3:10 PM, Viswanath Hariharan <[email protected]> > wrote: > > Sir > I have a doubt about the method you asked me to try to add non-linear > constraints. > The constraint I want to add is x'Hx + e'x + C < = N (where N is cost > let's say 20000 or 15000). > > The above method asks me to create 2 functions, one that calculates > gradient values and constraint values and the other that calculates Hessian > of one of the lagrangian term that consists of lambda. > > 1. Say f = x'Hx + e'x + C < = N, Should I be computing the hessian of > lambda*f ? How do I compute lambda? > 2. Also, could you guide me as to where should I be inputting N? > > Thank you. > > Regards > Viswanath > > On Thu, Oct 5, 2017 at 10:41 AM, Ray Zimmerman <[email protected]> wrote: > >> *(Btw, simply reply to the list, no need to copy the list owner)* >> >> MATPOWER 6.0 and earlier does not have the capability to add nonlinear >> constraints to the OPF. However, this feature was just added to the master >> branch in GitHub <https://github.com/MATPOWER/matpower/>. See options 2 >> or 3 under “Getting MATPOWER” in the README >> <https://github.com/MATPOWER/matpower/blob/master/README.md>. The PDF >> manual for the latest development version of MATPOWER can typically be >> found here: >> >> https://www.dropbox.com/s/3qkji1cuyi075uj/MATPOWER-manual.pdf?dl=0 >> >> You’ll probably want to use the method described in Section 7.1.2 for >> Nonlinear Constraints. In particular, you’ll want to look at the example >> mentioned in t_opf_mips(). >> >> Hope this helps, >> >> Ray >> >> >> >> On Oct 4, 2017, at 5:59 PM, Viswanath Hariharan <[email protected]> >> wrote: >> >> Hello Sir >> I want to add non linear cost constraints to the opf solver. >> cost = x'Hx + C'x + constant <= 20000 >> >> How do I use the add_constraints function to add this constraint? Should >> I be adding new fields to om and then should I be passing it to >> add_constraints? >> >> Regards >> Viswanath Hariharan >> >> >> > >
