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package org.apache.commons.math3.fitting.leastsquares;

import org.apache.commons.math3.fitting.leastsquares.LeastSquaresProblem.Evaluation;
import org.apache.commons.math3.optim.ConvergenceChecker;
import org.apache.commons.math3.util.Precision;

Check if an optimization has converged based on the change in computed RMS.
Since:
3.4/**
 * Check if an optimization has converged based on the change in computed RMS.
 *
 * @since 3.4
 */
public class EvaluationRmsChecker implements ConvergenceChecker<Evaluation> {

    
relative tolerance for comparisons. /** relative tolerance for comparisons. */
    private final double relTol;
    
absolute tolerance for comparisons. /** absolute tolerance for comparisons. */
    private final double absTol;

    
Create a convergence checker for the RMS with the same relative and absolute
tolerance.
Convenience constructor for when the relative and absolute tolerances are the same. Same as new EvaluationRmsChecker(tol, tol). 
Params:
tol – the relative and absolute tolerance.
See Also:
EvaluationRmsChecker(double, double)/**
     * Create a convergence checker for the RMS with the same relative and absolute
     * tolerance.
     *
     * <p>Convenience constructor for when the relative and absolute tolerances are the
     * same. Same as {@code new EvaluationRmsChecker(tol, tol)}.
     *
     * @param tol the relative and absolute tolerance.
     * @see #EvaluationRmsChecker(double, double)
     */
    public EvaluationRmsChecker(final double tol) {
        this(tol, tol);
    }

    
Create a convergence checker for the RMS with a relative and absolute tolerance.
The optimization has converged when the RMS of consecutive evaluations are equal
to within the given relative tolerance or absolute tolerance.
Params:
relTol – the relative tolerance.
absTol – the absolute tolerance.
See Also:
Precision.equals(double, double, double)
Precision.equalsWithRelativeTolerance(double, double, double)/**
     * Create a convergence checker for the RMS with a relative and absolute tolerance.
     *
     * <p>The optimization has converged when the RMS of consecutive evaluations are equal
     * to within the given relative tolerance or absolute tolerance.
     *
     * @param relTol the relative tolerance.
     * @param absTol the absolute tolerance.
     * @see Precision#equals(double, double, double)
     * @see Precision#equalsWithRelativeTolerance(double, double, double)
     */
    public EvaluationRmsChecker(final double relTol, final double absTol) {
        this.relTol = relTol;
        this.absTol = absTol;
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public boolean converged(final int iteration,
                             final Evaluation previous,
                             final Evaluation current) {
        final double prevRms = previous.getRMS();
        final double currRms = current.getRMS();
        return Precision.equals(prevRms, currRms, this.absTol) ||
                Precision.equalsWithRelativeTolerance(prevRms, currRms, this.relTol);
    }

}