samer@1: package eg.maths;
samer@1: import  samer.core.*;
samer@1: import  samer.core.types.*;
samer@1: import  samer.maths.*;
samer@1: import  samer.maths.opt.*;
samer@1: import  samer.nn.nonlin.*;
samer@1: 
samer@1: public class Optimizer implements Agent
samer@1: {
samer@1: 	Node     node=Node.push(new Node("optimizer"));
samer@1: 	Function fn;
samer@1: 	VDouble	a = new VDouble("a",-1);
samer@1: 	VDouble	b = new VDouble("b",0);
samer@1: 	VDouble	c = new VDouble("c",1);
samer@1: 
samer@1: 	MinimumBracket	br = new MinimumBracket();
samer@1: 	BrentMinimiser min = new BrentMinimiser();
samer@1: 
samer@1: 	public Optimizer()
samer@1: 	{
samer@1: 		Object obj = (Function)Space.get("function");
samer@1: 		if (obj==null) {
samer@1: 			fn = new CompoundFunction( new Square(), new Quadratic(1,0,-1));
samer@1: 		} else {
samer@1: 			if (obj instanceof Function) fn=(Function)obj;
samer@1: 			else if (obj instanceof FunctionOfVector) {
samer@1: 				FunctionOfVector vfn=(FunctionOfVector)obj;
samer@1: 				VVector x = (VVector)Space.get("vector");
samer@1: 				VVector d = new VVector("d",x.size());
samer@1: 				LineFunction linefn = new LineFunction(vfn,x.size());
samer@1: 				linefn.setBase(x.array());
samer@1: 				linefn.setDirection(d.array());
samer@1: 				fn=linefn;
samer@1: 			}
samer@1: 		}
samer@1: 
samer@1: 		br.setFunction(fn);
samer@1: 		min.setFunction(fn);
samer@1: 		min.setFractionalTolerance(0.0001);
samer@1: 		min.setAbsoluteTolerance(0.0001);
samer@1: 		min.setBracket(br);
samer@1: 
samer@1: 		Shell.showViewer(new FunctionPlotter( node, fn), "Function");
samer@1: 		Shell.showViewer(new FunctionPlotter( node, fn.derivative()), "Derivative");
samer@1: 		Shell.exposeCommands(this);
samer@1: 		Shell.exposeViewables();
samer@1: 	}
samer@1: 
samer@1: 	public void getCommands(Agent.Registry r) { 
samer@1: 		r.add("bracket").add("minimise"); 
samer@1: 	}
samer@1: 
samer@1: 	public void execute(String cmd, Environment env)
samer@1: 	{ 
samer@1: 		if (cmd.equals("bracket")) {
samer@1: 			br.setInitialPoints(a.value,b.value);
samer@1: 			br.run();
samer@1: 			a.value = br.ax; a.changed();
samer@1: 			b.value = br.bx; b.changed();
samer@1: 			c.value = br.cx; c.changed();
samer@1: 		} else if (cmd.equals("minimise")) {
samer@1: 			min.run();
samer@1: 			Shell.print("minimum at x="+min.getArgument());
samer@1: 			Shell.print("function value f(x)="+min.getValue());
samer@1: 			Shell.print("took "+min.getIterations()+" iterations");
samer@1: 		}
samer@1: 	}
samer@1: }