ChauvenetCriterionStatistics.h

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//# Copyright (C) 2000,2001
//# Associated Universities, Inc. Washington DC, USA.
//#
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//# $Id: Array.h 21545 2015-01-22 19:36:35Z gervandiepen $

#ifndef SCIMATH_CHAUVENETCRITERIONSTATISTICS_H
#define SCIMATH_CHAUVENETCRITERIONSTATISTICS_H

#include <casacore/casa/aips.h>

#include <casacore/scimath/Mathematics/ConstrainedRangeStatistics.h>

#include <set>
#include <vector>
#include <utility>

namespace casacore {

// Class to calculate statistics using the so-called Chauvenet criterion. This method
// iteratively calculates statistics by discarding outliers on the basis of Chauvenet's
// criterion, until the specified maximum number of iterations is reached, or the final
// iteration results in no additional points being discarded.
// Alternatively, one can specify a z score which indicates the number of standard deviations
// beyond which to discard points. In this case, no iterating is done.

template <class AccumType, class DataIterator, class MaskIterator=const Bool*, class WeightsIterator=DataIterator>
class ChauvenetCriterionStatistics
        : public ConstrainedRangeStatistics<CASA_STATP> {
public:

        // If <src>zscore</src> is not negative, use that value to discard outliers beyond
        // zscore standard deviations from the mean, and compute statistics based on the
        // remaining data. If <src>zscore</src> is negative, use Chauvenet's Criterion to
        // determine which outliers to discard. <src>maxIterations</src> is the maximum
        // number of iterations to use before stopping. If negative, continue iterating until the
        // set zscore or Chauvenet's criterion is met (ie that there are no remaining outliers).
        ChauvenetCriterionStatistics(Double zscore=-1, Int maxIterations=0);

        virtual ~ChauvenetCriterionStatistics();

        // copy semantics
        ChauvenetCriterionStatistics<CASA_STATP>& operator=(
                const ChauvenetCriterionStatistics<CASA_STATP>& other
        );

        // get the algorithm that this object uses for computing stats
        virtual StatisticsData::ALGORITHM algorithm() const {
                return StatisticsData::CHAUVENETCRITERION;
        };

        // reset object to initial state. Clears all private fields including data,
        // accumulators, global range. It does not affect the fence factor (_f), which was
        // set at object construction.
        virtual void reset();

        // This class does not allow statistics to be calculated as datasets are added, so
        // an exception will be thrown if <src>c</src> is True.
        void setCalculateAsAdded(Bool c);

        // get the number of iterations
        uInt getNiter() const { return _niter; }

private:

        Double _zscore;
        Int _maxIterations;
        Bool _rangeIsSet;
        uInt _niter;

        void _setRange();
};

}

#ifndef CASACORE_NO_AUTO_TEMPLATES
#include <casacore/scimath/Mathematics/ChauvenetCriterionStatistics.tcc>
#endif //# CASACORE_NO_AUTO_TEMPLATES

#endif