CGAL users discussion list

[Marc Glisse <>]

On Wed, 3 May 2023, Ashish Kashinath wrote:

> Hi, I was trying to understand the quadratic programming example given in
> the repo : first_qp.cpp
> <https://doc.cgal.org/latest/QP_solver/QP_solver_2first_qp_8cpp-example.html>
> The example here uses the objective function: (x^2 + 4*y^2 -32*y + 64), and
> uses set_d( ) and set_c( ) functions to setup the objective function
>
> My question is this : What if the objective function contained a term that
> is the product of the two variables such as this : (x^2 + 4*y^2 -32*y + 64
> + xy) ?
> How can I use set_d( ) in such a case? How would the coefficients need to
> be setup?

(up to a factor 2)

qp.set_d(X, X, 2);

represents X*X*2

qp.set_d (Y, Y, 8);

represents Y*Y*8

https://doc.cgal.org/latest/QP_solver/classCGAL_1_1Quadratic__program.html#a2b598d11d1d6daff9d20e43dc586257d
says
"sets the entries 2Dij and 2Dji of qp to val."

How about qp.set_d (Y, X, 84); 
?

--
Marc Glisse