/*
* Copyright (C) 2011-2015, Peter Abeles. All Rights Reserved.
*
* This file is part of Geometric Regression Library (GeoRegression).
*
* Licensed 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
*
* http://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 georegression.fitting.sphere;
import georegression.struct.point.Point3D_F64;
import georegression.struct.shapes.Sphere3D_F64;
import org.ddogleg.fitting.modelset.ModelFitter;
import org.ddogleg.optimization.FactoryOptimization;
import org.ddogleg.optimization.UnconstrainedLeastSquares;
import java.util.List;
/**
* {@link UnconstrainedLeastSquares} fitting of 3D points to a sphere.
*
* @author Peter Abeles
*/
public class FitSphereToPoints_F64 implements ModelFitter<Sphere3D_F64,Point3D_F64> {
// functions used by non-linear least squares solver
private SphereToPointSignedDistance_F64 function = new SphereToPointSignedDistance_F64();
private SphereToPointSignedDistanceJacobian_F64 jacobian = new SphereToPointSignedDistanceJacobian_F64();
// The solver
private UnconstrainedLeastSquares optimizer;
// need to convert sphere to double[]
private /**/double[] param = new /**/double[4];
// maximum number of iterations
private int maxIterations;
// tolerances for optimization
private /**/double ftol;
private /**/double gtol;
// used to convert double[] into shape parameters
private CodecSphere3D_F64 codec = new CodecSphere3D_F64();
/**
* Constructor which provides access to all tuning parameters
*
* @param optimizer Optimization algorithm
* @param maxIterations Maximum number of iterations that the optimizer can perform. Try 100
* @param ftol Convergence tolerance. See {@link UnconstrainedLeastSquares}.
* @param gtol Convergence tolerance. See {@link UnconstrainedLeastSquares}.
*/
public FitSphereToPoints_F64(UnconstrainedLeastSquares optimizer,
int maxIterations, /**/double ftol, /**/double gtol) {
this.optimizer = optimizer;
this.maxIterations = maxIterations;
this.ftol = ftol;
this.gtol = gtol;
}
/**
* Simplified constructor. Only process access to the maximum number of iterations.
* @param maxIterations Maximum number of iterations. Try 100
*/
public FitSphereToPoints_F64( int maxIterations ) {
this(FactoryOptimization.leastSquaresLM(1e-3,false),maxIterations,1e-12,0);
}
@Override
public boolean fitModel(List<Point3D_F64> dataSet, Sphere3D_F64 initial, Sphere3D_F64 found) {
codec.encode(initial,param);
function.setPoints(dataSet);
jacobian.setPoints(dataSet);
optimizer.setFunction(function,jacobian);
optimizer.initialize(param,ftol,gtol);
for( int i = 0; i < maxIterations; i++ ) {
if( optimizer.iterate() )
break;
}
codec.decode(optimizer.getParameters(),found);
return true;
}
}