1 files changed, 72 insertions, 0 deletions
diff --git a/gi/posterior-regularisation/prjava/src/optimization/projections/Projection.java b/gi/posterior-regularisation/prjava/src/optimization/projections/Projection.java
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+++ b/gi/posterior-regularisation/prjava/src/optimization/projections/Projection.java
@@ -0,0 +1,72 @@
+package optimization.projections;
+
+import optimization.util.MathUtils;
+import optimization.util.MatrixOutput;
+import util.ArrayMath;
+import util.Printing;
+
+
+
+public abstract class Projection {
+
+	
+	public abstract void project(double[] original);
+	
+	
+	/**
+	 *  From the projection theorem "Non-Linear Programming" page
+	 *  201 fact 2.
+	 *  
+	 *  Given some z in R, and a vector x* in X;
+	 *  x* = z+ iif for all x in X 
+	 *  (z-x*)'(x-x*) <= 0 where 0 is when x*=x
+	 *  See figure 2.16 in book
+	 *  
+	 * @param original
+	 * @param projected
+	 * @return
+	 */
+	public boolean testProjection(double[] original, double[] projected){
+		double[] original1 = original.clone();
+		//System.out.println(Printing.doubleArrayToString(original1, null, "original"));
+		//System.out.println(Printing.doubleArrayToString(projected, null, "projected"));
+		MathUtils.minusEquals(original1, projected, 1);
+		//System.out.println(Printing.doubleArrayToString(original1, null, "minus1"));
+		for(int i = 0; i < 10; i++){
+			double[] x = samplePoint(original.length);
+		//	System.out.println(Printing.doubleArrayToString(x, null, "sample"));
+			//If the same this returns zero so we are there.	
+			MathUtils.minusEquals(x, projected, 1);
+		//	System.out.println(Printing.doubleArrayToString(x, null, "minus2"));
+			double dotProd = MathUtils.dotProduct(original1, x);
+			
+		//	System.out.println("dot " + dotProd);
+			if(dotProd > 0) return false;
+		}
+		
+		//Perturbs the point a bit in all possible directions
+		for(int i = 0; i < original.length; i++){
+			double[] x = perturbePoint(projected,i);
+		//	System.out.println(Printing.doubleArrayToString(x, null, "perturbed"));
+			//If the same this returns zero so we are there.	
+			MathUtils.minusEquals(x, projected, 1);
+		//	System.out.println(Printing.doubleArrayToString(x, null, "minus2"));
+			double dotProd = MathUtils.dotProduct(original1, x);
+			
+		//	System.out.println("dot " + dotProd);
+			if(dotProd > 0) return false;
+		}
+		
+		
+		
+		return true;
+	}
+
+	//Samples a point from the constrained set
+	public abstract double[] samplePoint(int dimensions);
+	
+	//Perturbs a point a bit still leaving it at the constraints set
+	public abstract double[] perturbePoint(double[] point, int parameter);
+	
+	
+}