forum.alglib.net

I have a question on passing in variables using minlmoptimize.

For minlmoptimize the objective function must be of the the form:
objective_function(double[] initial_guess, double[] fi, object var)

However in place of object var I want to pass in an instance of my custom class (C):
Setup C = new Setup();
Thus I would have:
objective_function(double[] initial_guess, double[] fi, Setup C)

When I try to do this I get an error "cannot convert from method group to alglib.ndimensional_fvec"

I want to pass the instance of my class so the objective function can modify certain values in that class.

Thanks,
Scott

You have to convert object to your class Setup in the objective_function, without changing its signature. You can pass your own class, but as object only - however, you can easily convert it back to its original representation.

Sergey, thanks for the reply. How would I convert the object C back to class Setup?

http://msdn.microsoft.com/en-us/library/ms173105.aspx this article covers typecasting in C#

Ok, lets look at an example:

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
object O = new object();
Setup C = new Setup();
C.A = 2;
C.B = 3;

testfnc(C);

}

private static void testfnc(object C)
{
((ConsoleApplication1.Setup)(C)).A = 4;


}
}

public class Setup
{
public double A = 0;
public double B = 0;
}
}


How can I get my testfnc to use just C.A instead of ((ConsoleApplication1.Setup)(C)).A?

Thats what I am confused on right now.

Scott

I think that you can write Setup C2 = (ConsoleApplication1.Setup)C and work with C2.

But then C2 is a different instance of the same object. Therefore once I exit the objective function any variables that were changed to C2 I will not see.

I think that you should review basics of C# object model. Speaking short, C and C2 are references to the same underlying object. Hence, changes made to C2 will be instantly visible when you look at C.