MVAModuleHelper.h

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#ifndef PhysicsTools_MVAComputer_MVAModuleHelper_h
#define PhysicsTools_MVAComputer_MVAModuleHelper_h
// -*- C++ -*-
//
// Package:     MVAComputer
// Class  :     MVAModuleHelper
//

//
// Author:  Christophe Saout <christophe.saout@cern.ch>
// Created:     Sat Apr 24 15:18 CEST 2007
//

#include <functional>
#include <algorithm>
#include <numeric>
#include <cstring>
#include <string>
#include <vector>
#include <cmath>

#include <boost/bind.hpp>

#include "FWCore/Framework/interface/EventSetup.h"

#include "PhysicsTools/MVAComputer/interface/AtomicId.h"
#include "PhysicsTools/MVAComputer/interface/Calibration.h"
#include "PhysicsTools/MVAComputer/interface/MVAComputerCache.h"
#include "CondFormats/PhysicsToolsObjects/interface/MVAComputer.h"

namespace PhysicsTools {

template<typename Object>
struct MVAModuleHelperDefaultFiller {
    MVAModuleHelperDefaultFiller(const PhysicsTools::AtomicId &name) {}

    double operator()(const Object &object,
                      const PhysicsTools::AtomicId &name)
    { return object.compute(name); }
};

template<class Record, typename Object,
         class Filler = MVAModuleHelperDefaultFiller<Object> >
class MVAModuleHelper {
    public:
    MVAModuleHelper(const std::string &label) : label(label) {}
    MVAModuleHelper(const MVAModuleHelper &orig) : label(orig.label) {}
    ~MVAModuleHelper() {}

    void setEventSetup(const edm::EventSetup &setup);
    void setEventSetup(const edm::EventSetup &setup, const char *esLabel);

    double operator()(const Object &object) const;

    void train(const Object &object, bool target, double weight = 1.0) const;

    private:
    void init(const PhysicsTools::Calibration::MVAComputerContainer *container);

    const std::string       label;
    PhysicsTools::MVAComputerCache  cache;

    class Value {
        public:
            Value(const std::string &name) :
                name(name), filler(name) {}
            Value(const std::string &name, double value) :
            name(name), filler(name), value(value) {}

        inline bool update(const Object &object) const
        {
            value = filler(object, name);
            return !std::isfinite(value);
        }

        PhysicsTools::AtomicId getName() const { return name; }
        double getValue() const { return value; }

        private:
        PhysicsTools::AtomicId      name;
        Filler              filler;

        mutable double          value;
    };

    std::vector<Value>          values;
};

template<class Record, typename Object, class Filler>
void MVAModuleHelper<Record, Object, Filler>::setEventSetup(
                        const edm::EventSetup &setup)
{
    edm::ESHandle<PhysicsTools::Calibration::MVAComputerContainer> handle;
    setup.get<Record>().get(handle);
    const PhysicsTools::Calibration::MVAComputerContainer *container = handle.product();
    if (cache.update(container, label.c_str()) && cache)
        init(container);
}

template<class Record, typename Object, class Filler>
void MVAModuleHelper<Record, Object, Filler>::setEventSetup(
            const edm::EventSetup &setup, const char *esLabel)
{
    edm::ESHandle<PhysicsTools::Calibration::MVAComputerContainer> handle;
    setup.get<Record>().get(esLabel, handle);
    const PhysicsTools::Calibration::MVAComputerContainer *container = handle.product();
    if (cache.update(container, label.c_str()) && cache)
        init(container);
}

template<class Record, typename Object, class Filler>
void MVAModuleHelper<Record, Object, Filler>::init(
    const PhysicsTools::Calibration::MVAComputerContainer *container)
{
    const std::vector<PhysicsTools::Calibration::Variable> &vars =
                    container->find(label).inputSet;
    values.clear();
    for(std::vector<PhysicsTools::Calibration::Variable>::const_iterator
            iter = vars.begin(); iter != vars.end(); ++iter)
        if (std::strncmp(iter->name.c_str(), "__", 2) != 0)
            values.push_back(Value(iter->name));
}

template<class Record, typename Object, class Filler>
double MVAModuleHelper<Record, Object, Filler>::operator()(
                        const Object &object) const
{
    std::for_each(values.begin(), values.end(),
                  boost::bind(&Value::update, _1, object));
    return cache->eval(values);
}

template<class Record, typename Object, class Filler>
void MVAModuleHelper<Record, Object, Filler>::train(
        const Object &object, bool target, double weight) const
{
    static const PhysicsTools::AtomicId kTargetId("__TARGET__");
    static const PhysicsTools::AtomicId kWeightId("__WEIGHT__");

    if (!cache)
        return;

    using boost::bind;
    if (std::accumulate(values.begin(), values.end(), 0,
                        bind(std::plus<int>(), _1,
                             bind(&Value::update, _2, object))))
        return;

    PhysicsTools::Variable::ValueList list;
    list.add(kTargetId, target);
    list.add(kWeightId, weight);
    for(typename std::vector<Value>::const_iterator iter = values.begin();
        iter != values.end(); ++iter)
        list.add(iter->getName(), iter->getValue());

    cache->eval(list);
}

} // namespace PhysicsTools

#endif // PhysicsTools_MVAComputer_MVAModuleHelper_h