Adding NLDF example

images, source code (.java), and Readme

Author: caleb-hamilton

NLDF/GenDFEx.java

@@ -0,0 +1,209 @@
+import com.nag.routines.E04.E04GN; // nagf_opt_handle_solve_nldf
+import com.nag.routines.E04.E04GNU; // monit
+import com.nag.routines.E04.E04GNX; // confun dummy
+import com.nag.routines.E04.E04GNY; // congrd dummy
+import com.nag.routines.E04.E04RA; // Handle init
+import com.nag.routines.E04.E04RH; //box bounds
+import com.nag.routines.E04.E04RJ; // linear constraints
+import com.nag.routines.E04.E04RM; // add model and residual sparsity structure
+import com.nag.routines.E04.E04RZ; //destroy handle
+import com.nag.routines.E04.E04ZM; // optional parameters
+
+import java.lang.Math;
+import java.util.Arrays;
+//import java.io.File;
+//import java.io.IOException;
+///import java.io.FileWriter;
+
+public class GenDFEx {
+
+    public static void main (String[] args) {
+
+        E04GN e04gn = new E04GN(); // the solver
+        E04RA e04ra = new E04RA(); // the handle initializer
+        E04RM e04rm = new E04RM(); // for setting model and residual sparsity structure
+        E04ZM e04zm = new E04ZM(); // for setting optional parameters
+        E04RZ e04rz = new E04RZ(); // handle destroyer
+
+
+        MONIT monit = new MONIT(); // defined below using E04GNU
+        CONFUN confun = new CONFUN(); // defined below using E04GNX (dummy)
+        CONGRD congrd = new CONGRD(); // defined below using E04GNY (dummy)
+
+
+        // Set up data and initial handle parameters
+        double [] t = linspace(0.5, 2.5, 21);
+        double [] ruser1 = toydata1(t); // For Example 1
+        double [] ruser2 = toydata2(t); // For Example 2
+
+        double [] x = new double [2]; // instatiate an array for as many variable you need 
+        long handle = 0;
+        int nvar = x.length;
+        int ifail;
+        int nres = t.length;
+
+        // Init for sparsity structure
+        int isparse = 0;
+        int nnzrd = 0;
+        int [] irowrd = new int [nnzrd];
+        int [] icolrd = new int [nnzrd];
+
+
+
+        // Get handle
+        ifail = 0;
+        e04ra.eval(handle, nvar, ifail);
+        handle = e04ra.getHANDLE();
+
+        // define the residual functions and sparsity structure
+        ifail = 0;
+        e04rm.eval(handle, nres, isparse, nnzrd, irowrd, icolrd, ifail);
+
+        // Set options
+        ifail = 0;
+        e04zm.eval(handle, "NLDF Loss Function Type = L2", ifail);
+        e04zm.eval(handle, "Print Level = 1", ifail);
+        e04zm.eval(handle, "Print Options = No", ifail);
+        e04zm.eval(handle, "Print Solution = Yes", ifail);
+
+        // Initialize all the remaining parameters
+        LSQFUN lsqfun = new LSQFUN();
+        LSQGRD lsqgrd = new LSQGRD();
+        double [] rx = new double[nres];
+        double [] rinfo = new double[100];
+        double [] stats = new double [100];
+        int [] iuser = new int[0];
+        long cpuser = 0;
+
+        // Solve
+        System.out.println("\n----Solving Toy Dataset #1 with L2 Loss Function----");
+        ifail = 0;
+        x = init_x(); //give x the initial guess you want to start from
+                      // x will be changed during solve
+        e04gn.eval(handle, lsqfun, lsqgrd, confun, congrd, monit, nvar, x, nres, rx, rinfo,
+            stats, iuser, ruser1, cpuser, ifail);
+
+        System.out.println("\n----Solving Toy Dataset #1 with L1 Loss Function----");
+        ifail = 0;
+        x = init_x();
+        e04zm.eval(handle, "NLDF Loss Function Type = L1", ifail);
+        e04gn.eval(handle, lsqfun, lsqgrd, confun, congrd, monit, nvar, x, nres, rx, rinfo,
+            stats, iuser, ruser1, cpuser, ifail);
+
+
+
+        // The trade-off of a loss function
+        // The handle can keep getting used. We are only changing the data passed to the
+        // solver using ruser2 (first 3 and last 3 data points different from middle)
+        System.out.println("\n----Solving Toy Dataset #2 with L2 Loss Function----");
+        ifail = 0;
+        x = init_x();
+        e04zm.eval(handle, "NLDF Loss Function Type = L2", ifail);
+        e04gn.eval(handle, lsqfun, lsqgrd, confun, congrd, monit, nvar, x, nres, rx, rinfo,
+            stats, iuser, ruser2, cpuser, ifail);
+
+        System.out.println("\n----Solving Toy Dataset #2 with L1 Loss Function----");
+        ifail = 0;
+        x = init_x();
+        e04zm.eval(handle, "NLDF Loss Function Type = L1", ifail);
+        e04gn.eval(handle, lsqfun, lsqgrd, confun, congrd, monit, nvar, x, nres, rx, rinfo,
+            stats, iuser, ruser2, cpuser, ifail);
+
+        System.out.println("\n----Solving Toy Dataset #2 with ATAN Loss Function----");
+        ifail = 0;
+        x = init_x();
+        e04zm.eval(handle, "NLDF Loss Function Type = ATAN", ifail);
+        e04gn.eval(handle, lsqfun, lsqgrd, confun, congrd, monit, nvar, x, nres, rx, rinfo,
+            stats, iuser, ruser2, cpuser, ifail);
+
+        e04rz.eval(handle,ifail); // destroy the handle
+        
+    }
+
+
+    private static class LSQFUN extends E04GN.Abstract_E04GN_LSQFUN {
+        public void eval() {
+            for(int i = 0; i < NRES; i++){
+                this.RX[i] = RUSER[NRES + i] - X[0] * Math.sin(X[1] * RUSER[i]);
+            }
+        }
+    }
+
+    private static class LSQGRD extends E04GN.Abstract_E04GN_LSQGRD {
+        public void eval() {
+            for(int i = 0; i < NRES; i++){
+                this.RDX[i * NVAR] = (-1 * Math.sin(X[1]*RUSER[i]));
+                this.RDX[i* NVAR + 1] = (-1 * RUSER[i] * X[0] * Math.cos(X[1] * RUSER[i]));
+            }
+        }
+    }
+
+    // Dummy Functions required for NLDF solver
+    private static class CONFUN extends E04GNX implements E04GN.E04GN_CONFUN {
+        public void eval(){
+            super.eval();
+        }
+    }
+
+    private static class CONGRD extends E04GNY implements E04GN.E04GN_CONGRD {
+        public void eval(){
+            super.eval();
+        }
+    }
+
+    private static class MONIT extends E04GNU implements E04GN.E04GN_MONIT {
+        public void eval(){
+            super.eval();
+        }
+    }
+    
+    // Utilities for setting up data for problem
+    private static double[] linspace(double startPoint, double endPoint, int length) {
+        double[] a = new double[length];
+        double step = (endPoint - startPoint) / (length - 1);
+        a[0] = startPoint;
+        a[length - 1] = endPoint;
+        for (int i = 1; i < length - 1; i++) {
+            a[i] = startPoint + i * step;
+        }
+        return a;
+    }
+
+    private static double[] toydata1(double [] t) {
+        double [] y = new double[t.length * 2];
+        for(int i = 0; i < t.length * 2; i++){
+            if(i < t.length){
+                y[i] = t[i];
+            }
+            else{
+                y[i] = Math.sin(t[i-t.length]);
+                if(i -  t.length == 10){
+                    y[i] = 5 * y[i];
+                }
+            }
+        }
+        return y;
+    }
+    
+    private static double[] toydata2(double [] t) {
+        double [] y = new double[t.length * 2];
+        for(int i = 0; i < t.length * 2; i++){
+            if(i < t.length){
+                y[i] = t[i];
+            }
+            else{
+                y[i] = Math.sin(t[i-t.length]);
+                if((i -  t.length >= 3) && (i - t.length < 18)){
+                    y[i] = 5 * y[i];
+                }
+            }
+        }
+        return y;
+    }
+
+    // For resetting the initial guess
+    private static double[] init_x() {
+        double [] x = new double [] {2.1,1.4};
+        return x;
+    }
+}