void IDDecoyProbability::apply_(vector<PeptideIdentification> & ids, const vector<double> & rev_scores, const vector<double> & fwd_scores, const vector<double> & all_scores)
  {
    Size number_of_bins(param_.getValue("number_of_bins"));



    // normalize distribution to [0, 1]
    vector<double> fwd_scores_normalized(number_of_bins, 0.0), rev_scores_normalized(number_of_bins, 0.0), diff_scores(number_of_bins, 0.0), all_scores_normalized(number_of_bins, 0.0);
    Transformation_ rev_trafo, fwd_trafo, all_trafo;
    normalizeBins_(rev_scores, rev_scores_normalized, rev_trafo);
    normalizeBins_(fwd_scores, fwd_scores_normalized, fwd_trafo);
    normalizeBins_(all_scores, all_scores_normalized, all_trafo);

    // rev scores fitting
    vector<DPosition<2> > rev_data;

    for (Size i = 0; i < number_of_bins; ++i)
    {
      DPosition<2> pos;
      pos.setX(((double)i) / (double)number_of_bins + 0.0001);    // necessary????
      pos.setY(rev_scores_normalized[i]);
      rev_data.push_back(pos);
#ifdef IDDECOYPROBABILITY_DEBUG
      cerr << pos.getX() << " " << pos.getY() << endl;
#endif
    }

    Math::GammaDistributionFitter gdf;
    Math::GammaDistributionFitter::GammaDistributionFitResult result_gamma_1st (1.0, 3.0);
    gdf.setInitialParameters(result_gamma_1st);
    // TODO heuristic for good start parameters
    Math::GammaDistributionFitter::GammaDistributionFitResult result_gamma = gdf.fit(rev_data);

#ifdef IDDECOYPROBABILITY_DEBUG
    cerr << gdf.getGnuplotFormula() << endl;
    String rev_filename = param_.getValue("rev_filename");
    generateDistributionImage_(rev_scores_normalized, gdf.getGnuplotFormula(), rev_filename);
#endif

    // generate diffs of distributions
    // get the fwd and rev distribution, apply all_trafo and calculate the diff
    vector<Size> fwd_bins(number_of_bins, 0), rev_bins(number_of_bins, 0);
    double min(all_trafo.min_score), diff(all_trafo.diff_score);
    Size max_bin(0);
    for (vector<double>::const_iterator it = fwd_scores.begin(); it != fwd_scores.end(); ++it)
    {
      Size bin = (Size)((*it - min) / diff * (double)(number_of_bins - 1));
      ++fwd_bins[bin];
      if (fwd_bins[bin] > max_bin)
      {
        max_bin = fwd_bins[bin];
      }
    }

    Size max_reverse_bin(0), max_reverse_bin_value(0);
    //min = rev_trafo.min_score;
    //diff = rev_trafo.diff_score;
    for (vector<double>::const_iterator it = rev_scores.begin(); it != rev_scores.end(); ++it)
    {
      Size bin = (Size)((*it - min) / diff * (double)number_of_bins);
      ++rev_bins[bin];
      if (rev_bins[bin] > max_bin)
      {
        max_bin = rev_bins[bin];
      }
      if (rev_bins[bin] > max_reverse_bin_value)
      {
        max_reverse_bin = bin;
        max_reverse_bin_value = rev_bins[bin];
      }
    }

#ifdef IDDECOYPROBABILITY_DEBUG
    cerr << "Trying to get diff scores" << endl;
#endif

    // get diff of fwd and rev
    for (Size i = 0; i < number_of_bins; ++i)
    {
      Size fwd(0), rev(0);
      fwd = fwd_bins[i];
      rev = rev_bins[i];
      if ((double)fwd > (double)(1.3 * rev) && max_reverse_bin < i)
      {
        diff_scores[i] = (double)(fwd - rev) / (double)max_bin;
      }
      else
      {
        diff_scores[i] = 0.0;
      }
    }
#ifdef IDDECOYPROBABILITY_DEBUG
    cerr << "Gauss Fitting values size of diff scores=" << diff_scores.size() << endl;
#endif
    // diff scores fitting
    vector<DPosition<2> > diff_data;
    double gauss_A(0), gauss_x0(0), norm_factor(0);
    for (Size i = 0; i < number_of_bins; ++i)
    {
      DPosition<2> pos;
      pos.setX((double)i / (double)number_of_bins);
      pos.setY(diff_scores[i]);

      if (pos.getY() > gauss_A)
      {
        gauss_A = pos.getY();
      }
      gauss_x0 += pos.getX() * pos.getY();
      norm_factor += pos.getY();


      diff_data.push_back(pos);
    }

    double gauss_sigma(0);
    gauss_x0 /= (double)diff_data.size();
    gauss_x0 /= norm_factor;

    for (Size i = 0; i <= number_of_bins; ++i)
    {
      gauss_sigma += fabs(gauss_x0 - (double)i / (double)number_of_bins);
    }

    gauss_sigma /= (double)diff_data.size();



#ifdef IDDECOYPROBABILITY_DEBUG
    cerr << "setting initial parameters: " << endl;
#endif
    Math::GaussFitter gf;
    Math::GaussFitter::GaussFitResult result_1st(gauss_A, gauss_x0, gauss_sigma);
    gf.setInitialParameters(result_1st);
#ifdef IDDECOYPROBABILITY_DEBUG
    cerr << "Initial Gauss guess: A=" << gauss_A << ", x0=" << gauss_x0 << ", sigma=" << gauss_sigma << endl;
#endif

    //TODO: fail-to-fit correction was done using the GNUPlotFormula. Seemed to be a hack.
    //Changed it to try-catch-block but I am not sure if this correction should be made
    //at all. Can someone please verify?
    Math::GaussFitter::GaussFitResult result_gauss (gauss_A, gauss_x0, gauss_sigma);
    try{
        result_gauss = gf.fit(diff_data);
    }
    catch(Exception::UnableToFit& /* e */)
    {
      result_gauss.A = gauss_A;
      result_gauss.x0 = gauss_x0;
      result_gauss.sigma = gauss_sigma;
    }

//    // fit failed?
//    if (gf.getGnuplotFormula() == "")
//    {
//      result_gauss.A = gauss_A;
//      result_gauss.x0 = gauss_x0;
//      result_gauss.sigma = gauss_sigma;
//    }

#ifdef IDDECOYPROBABILITY_DEBUG
    cerr << gf.getGnuplotFormula() << endl;
    String fwd_filename = param_.getValue("fwd_filename");
    if (gf.getGnuplotFormula() == "")
    {
      String formula("f(x)=" + String(gauss_A) + " * exp(-(x - " + String(gauss_x0) + ") ** 2 / 2 / (" + String(gauss_sigma) + ") ** 2)");
      generateDistributionImage_(diff_scores, formula, fwd_filename);
    }
    else
    {
      generateDistributionImage_(diff_scores, gf.getGnuplotFormula(), fwd_filename);
    }
#endif

#ifdef IDDECOYPROBABILITY_DEBUG
    //all_trafo.diff_score + all_trafo.min_score
    String gauss_formula("f(x)=" + String(result_gauss.A / all_trafo.max_intensity) + " * exp(-(x - " + String(result_gauss.x0 * all_trafo.diff_score + all_trafo.min_score) + ") ** 2 / 2 / (" + String(result_gauss.sigma * all_trafo.diff_score)   + ") ** 2)");

    String b_str(result_gamma.b), p_str(result_gamma.p);
    String gamma_formula = "g(x)=(" + b_str + " ** " + p_str + ") / gamma(" + p_str + ") * x ** (" + p_str + " - 1) * exp(- " + b_str + " * x)";

    generateDistributionImage_(all_scores_normalized, all_trafo, gauss_formula, gamma_formula, (String)param_.getValue("fwd_filename"));
#endif

    vector<PeptideIdentification> new_prob_ids;
    // calculate the probabilities and write them to the IDs
    for (vector<PeptideIdentification>::const_iterator it = ids.begin(); it != ids.end(); ++it)
    {
      if (it->getHits().size() > 0)
      {
        vector<PeptideHit> hits;
        String score_type = it->getScoreType() + "_score";
        for (vector<PeptideHit>::const_iterator pit = it->getHits().begin(); pit != it->getHits().end(); ++pit)
        {
          PeptideHit hit = *pit;
          double score = hit.getScore();
          if (!it->isHigherScoreBetter())
          {
            score = -log10(score);
          }
          hit.setMetaValue(score_type, hit.getScore());
          hit.setScore(getProbability_(result_gamma, rev_trafo, result_gauss, fwd_trafo, score));
          hits.push_back(hit);
        }
        PeptideIdentification id = *it;
        id.setHigherScoreBetter(true);
        id.setScoreType(id.getScoreType() + "_DecoyProbability");
        id.setHits(hits);

        new_prob_ids.push_back(id);
      }
    }
    ids = new_prob_ids;
  }
Esempio n. 2
0
  p2[2] = 3.0;
  TEST_EQUAL((p1 + p2) ==  p3, true);
END_SECTION

START_SECTION((DPosition(CoordinateType x, CoordinateType y)))
	DPosition<2> p1(11.0f,12.1f);
	TEST_REAL_SIMILAR(p1[0],11.0f);
	TEST_REAL_SIMILAR(p1[1],12.1f);
  DPosition<2> p(12.34,56.78);
  TEST_REAL_SIMILAR(p[0], 12.34)
  TEST_REAL_SIMILAR(p[1], 56.78)
END_SECTION

START_SECTION((CoordinateType getX() const))
	DPosition<2> p1(11.0f,12.1f);
	TEST_REAL_SIMILAR(p1.getX(),11.0f);
END_SECTION

START_SECTION((CoordinateType getY() const))
	DPosition<2> p1(11.0f,12.1f);
	TEST_REAL_SIMILAR(p1.getY(),12.1f);
END_SECTION

START_SECTION((void setX(CoordinateType c)))
	DPosition<2> p1(11.0f,12.1f);
	p1.setX(5.0f);
	TEST_REAL_SIMILAR(p1[0],5.0f);
	TEST_REAL_SIMILAR(p1[1],12.1f);
END_SECTION

START_SECTION((void setY(CoordinateType c)))