src/kenlm/lm/interpolate/tune_derivatives.hh

#ifndef LM_INTERPOLATE_TUNE_DERIVATIVES_H
#define LM_INTERPOLATE_TUNE_DERIVATIVES_H

#include "lm/interpolate/tune_instance.hh"

#include <Eigen/Core>
#include <cmath>

namespace lm { namespace interpolate {

class ComputeDerivative {
  public:
    explicit ComputeDerivative(const util::FixedArray<Instance> &instances, const Matrix &ln_unigrams, WordIndex bos);

    Accum Iteration(const Vector &weights, Vector &gradient, Matrix &hessian);

  private:
    const util::FixedArray<Instance> &instances_;
    const Matrix &ln_unigrams_;

    const WordIndex bos_;

    // neg_correct_summed_(i) = -\sum_n ln p_i(w_n | w_1^{n-1})
    Vector neg_correct_summed_;
};

}} // namespaces

#endif // LM_INTERPOLATE_TUNE_DERIVATIVES_H