/*
    * Licensed to the Hipparchus project under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The Hipparchus project licenses this file to You under the Apache License, Version 2.0
    * (the "License"); you may not use this file except in compliance with
    * the License.  You may obtain a copy of the License at
    *
    *      https://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.hipparchus.optim.nonlinear.vector.leastsquares;
  
  import org.hipparchus.exception.LocalizedCoreFormats;
  import org.hipparchus.exception.MathIllegalStateException;
  import org.hipparchus.geometry.euclidean.threed.Plane;
  import org.hipparchus.geometry.euclidean.threed.Vector3D;
  import org.hipparchus.linear.SingularValueDecomposer;
  import org.hipparchus.optim.SimpleVectorValueChecker;
  import org.hipparchus.optim.nonlinear.vector.leastsquares.LeastSquaresOptimizer.Optimum;
  import org.hipparchus.optim.nonlinear.vector.leastsquares.LeastSquaresProblem.Evaluation;
  import org.hipparchus.util.FastMath;
  import org.junit.jupiter.api.Test;
  
  import java.io.IOException;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  
  /**
   * <p>Some of the unit tests are re-implementations of the MINPACK <a
   * href="http://www.netlib.org/minpack/ex/file17">file17</a> and <a
   * href="http://www.netlib.org/minpack/ex/file22">file22</a> test files.
   * The redistribution policy for MINPACK is available <a
   * href="http://www.netlib.org/minpack/disclaimer">here</a>/
   *
   */
  public class SequentialGaussNewtonOptimizerWithSVDTest
      extends AbstractSequentialLeastSquaresOptimizerAbstractTest {
  
      @Override
      public int getMaxIterations() {
          return 1000;
      }
  
      @Override
      public void defineOptimizer(Evaluation evaluation) {
          this.optimizer = new SequentialGaussNewtonOptimizer().
                           withDecomposer(new SingularValueDecomposer()).
                           withFormNormalEquations(false).
                           withEvaluation(evaluation);
      }
  
      @Test
      void testMaxEvaluations() throws Exception {
          try {
              CircleVectorial circle = new CircleVectorial();
              circle.addPoint( 30.0,  68.0);
              circle.addPoint( 50.0,  -6.0);
              circle.addPoint(110.0, -20.0);
              circle.addPoint( 35.0,  15.0);
              circle.addPoint( 45.0,  97.0);
  
              LeastSquaresProblem lsp = builder(circle)
                              .checkerPair(new SimpleVectorValueChecker(1e-30, 1e-30))
                              .maxIterations(Integer.MAX_VALUE)
                              .start(new double[]{98.680, 47.345})
                              .build();
  
              defineOptimizer(null);
              optimizer.optimize(lsp);
  
              customFail(optimizer);
          } catch (MathIllegalStateException e) {
              assertEquals(LocalizedCoreFormats.MAX_COUNT_EXCEEDED, e.getSpecifier());
          }
      }
  
  
      @Override
      @Test
      public void testHahn1() throws IOException {
          try {
              /*
               * When NOT FORMING normal equations, the optimizer diverges and hit max evaluations.
               * When FORMING normal equations, the optimizer converges,
               * but the results are very bad
               */
              super.testHahn1();
              customFail(optimizer);
          } catch (MathIllegalStateException e) {
              assertEquals(LocalizedCoreFormats.MAX_COUNT_EXCEEDED, e.getSpecifier());
          }
      }
 
     @Test
     @Override
     public void testGetIterations() {
         /* this diverges with SVD and no normal equations */
         try {
             super.testGetIterations();
             customFail(optimizer);
         } catch (MathIllegalStateException e) {
             assertEquals(LocalizedCoreFormats.MAX_COUNT_EXCEEDED,
                                 e.getSpecifier());
         }
     }
 
     @Test
     @Override
     public void testNonInvertible() throws Exception {
         /*  SVD can compute a solution to singular problems.
          *  In this case the target vector, b, is not in the
          *  span of the jacobian matrix, A. The closest point
          *  to b on the plane spanned by A is computed.
          */
         LinearProblem problem = new LinearProblem(new double[][]{
                 {1, 2, -3},
                 {2, 1, 3},
                 {-3, 0, -9}
         }, new double[]{1, 1, 1});
 
         defineOptimizer(null);
         Optimum optimum = optimizer.optimize(problem.getBuilder().build());
 
         Plane span = new Plane(Vector3D.ZERO, new Vector3D(1, 2, -3), new Vector3D(2, 1, 0), TOl);
         double expected = FastMath.abs(span.getOffset(new Vector3D(1, 1, 1)));
         double actual = optimum.getResiduals().getNorm();
 
         //verify
         assertEquals(expected, actual, TOl);
     }
 
 }