Program: 144197
Project: 144197
Buggy source:
public Vector solve(){
  Matrix J=objective.getJ();
  Vector y=objective.getY();
  int n=J.getColumnDimension();
switch (method) {
case CHOLESKY_DECOMPOSITION:
    CholeskyDecomposition choleskyDecomposition=new CholeskyDecomposition(J.transpose().multiply(J));
  try {
    return choleskyDecomposition.solve(J.transpose().multiply(y));
  }
 catch (  NonSymmetricMatrixException e) {
    System.err.println("String_Node_Str" + "String_Node_Str");
    this.method=Method.SINGULAR_VALUE_DECOMPOSITION;
    return solve();
  }
catch (  NonPositiveDefiniteMatrixException e) {
    System.err.println("String_Node_Str" + "String_Node_Str" + "String_Node_Str");
    this.method=Method.SINGULAR_VALUE_DECOMPOSITION;
    return solve();
  }
case QR_DECOMPOSITION:
try {
  QRDecomposition qrDecomposition=new QRDecomposition(J);
  return qrDecomposition.solve(y);
}
 catch (SingularMatrixException e) {
  System.err.println("String_Node_Str" + "String_Node_Str" + "String_Node_Str");
  this.method=Method.SINGULAR_VALUE_DECOMPOSITION;
  return solve();
}
case SINGULAR_VALUE_DECOMPOSITION:
SingularValueDecomposition singularValueDecomposition=new SingularValueDecomposition(J);
return singularValueDecomposition.solve(y);
case CONJUGATE_GRADIENT:
try {
LinearLeastSquaresFunction objective=new LinearLeastSquaresFunction(J,y);
ConjugateGradientSolver conjugateGradientSolver=new ConjugateGradientSolver.Builder(objective,new double[n]).preconditioningMethod(ConjugateGradientSolver.PreconditioningMethod.SYMMETRIC_SUCCESSIVE_OVER_RELAXATION).build();
return conjugateGradientSolver.solve();
}
 catch (NonPositiveDefiniteMatrixException e) {
System.err.println("String_Node_Str" + "String_Node_Str" + "String_Node_Str");
this.method=Method.SINGULAR_VALUE_DECOMPOSITION;
return solve();
}
default :
throw new NotImplementedException();
}
}

Fixed version (ground truth):
public Vector solve(){
  Matrix J=objective.getJ();
  Vector y=objective.getY();
  int n=J.getColumnDimension();
switch (method) {
case CHOLESKY_DECOMPOSITION:
    CholeskyDecomposition choleskyDecomposition=new CholeskyDecomposition(J.transpose().multiply(J));
  try {
    return choleskyDecomposition.solve(J.transpose().multiply(y));
  }
 catch (  NonSymmetricMatrixException e) {
    System.err.println("String_Node_Str" + "String_Node_Str");
    this.method=Method.SINGULAR_VALUE_DECOMPOSITION;
    return solve();
  }
catch (  NonPositiveDefiniteMatrixException e) {
    System.err.println("String_Node_Str" + "String_Node_Str" + "String_Node_Str");
    this.method=Method.SINGULAR_VALUE_DECOMPOSITION;
    return solve();
  }
case QR_DECOMPOSITION:
try {
  QRDecomposition qrDecomposition=new QRDecomposition(J);
  return qrDecomposition.solve(y);
}
 catch (SingularMatrixException e) {
  System.err.println("String_Node_Str" + "String_Node_Str" + "String_Node_Str");
  this.method=Method.SINGULAR_VALUE_DECOMPOSITION;
  return solve();
}
case SINGULAR_VALUE_DECOMPOSITION:
SingularValueDecomposition singularValueDecomposition=new SingularValueDecomposition(J);
return singularValueDecomposition.solve(y);
case CONJUGATE_GRADIENT:
try {
LinearLeastSquaresFunction objective=new LinearLeastSquaresFunction(J,y);
ConjugateGradientSolver conjugateGradientSolver=new ConjugateGradientSolver.Builder(objective,new double[n]).preconditioningMethod(ConjugateGradientSolver.PreconditioningMethod.SYMMETRIC_SUCCESSIVE_OVER_RELAXATION).buildWithChecking();
return conjugateGradientSolver.solve();
}
 catch (NonPositiveDefiniteMatrixException e) {
System.err.println("String_Node_Str" + "String_Node_Str" + "String_Node_Str");
this.method=Method.SINGULAR_VALUE_DECOMPOSITION;
return solve();
}
default :
throw new NotImplementedException();
}
}