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package optimization.gradientBasedMethods;
import java.util.ArrayList;
import optimization.util.MathUtils;
public class DebugHelpers {
public static void getLineSearchGraph(Objective o, double[] direction,
double[] parameters, double originalObj,
double originalDot, double c1, double c2){
ArrayList<Double> stepS = new ArrayList<Double>();
ArrayList<Double> obj = new ArrayList<Double>();
ArrayList<Double> norm = new ArrayList<Double>();
double[] gradient = new double[o.getNumParameters()];
double[] newParameters = parameters.clone();
MathUtils.plusEquals(newParameters,direction,0);
o.setParameters(newParameters);
double minValue = o.getValue();
int valuesBiggerThanMax = 0;
for(double step = 0; step < 2; step +=0.01 ){
newParameters = parameters.clone();
MathUtils.plusEquals(newParameters,direction,step);
o.setParameters(newParameters);
double newValue = o.getValue();
gradient = o.getGradient();
double newgradDirectionDot = MathUtils.dotProduct(gradient,direction);
stepS.add(step);
obj.add(newValue);
norm.add(newgradDirectionDot);
if(newValue <= minValue){
minValue = newValue;
}else{
valuesBiggerThanMax++;
}
if(valuesBiggerThanMax > 10){
break;
}
}
System.out.println("step\torigObj\tobj\tsuffdec\tnorm\tcurvature1");
for(int i = 0; i < stepS.size(); i++){
double cnorm= norm.get(i);
System.out.println(stepS.get(i)+"\t"+originalObj +"\t"+obj.get(i) + "\t" +
(originalObj + originalDot*((Double)stepS.get(i))*c1) +"\t"+Math.abs(cnorm) +"\t"+c2*Math.abs(originalDot));
}
}
public static double[] getNumericalGradient(Objective o, double[] parameters, double epsilon){
int nrParameters = o.getNumParameters();
double[] gradient = new double[nrParameters];
double[] newParameters;
double originalValue = o.getValue();
for(int parameter = 0; parameter < nrParameters; parameter++){
newParameters = parameters.clone();
newParameters[parameter]+=epsilon;
o.setParameters(newParameters);
double newValue = o.getValue();
gradient[parameter]=(newValue-originalValue)/epsilon;
}
return gradient;
}
}
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