BlockSolver.cc

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#include "Calibration/Tools/interface/BlockSolver.h"
#include "FWCore/MessageLogger/interface/MessageLogger.h"
int BlockSolver::operator()(const CLHEP::HepMatrix& matrix, const CLHEP::HepVector& vector, CLHEP::HepVector& result) {
  double threshold = matrix.trace() / static_cast<double>(matrix.num_row());
  std::vector<int> holes;
  // loop over the matrix rows
  for (int row = 0; row < matrix.num_row(); ++row) {
    double sumAbs = 0.;
    for (int col = 0; col < matrix.num_col(); ++col)
      sumAbs += fabs(matrix[row][col]);
    if (sumAbs < threshold)
      holes.push_back(row);
  }  // loop over the matrix rows

  int dim = matrix.num_col() - holes.size();

  if (holes.empty())  //PG exceptional case!
  {
    for (int i = 0; i < result.num_row(); ++i)
      result[i] = 1.;
  } else if (dim > 0) {
    CLHEP::HepMatrix solution(dim, dim, 0);
    CLHEP::HepVector input(dim, 0);
    shrink(matrix, solution, vector, input, holes);
    CLHEP::HepVector output = solve(solution, input);
    pour(result, output, holes);
  }
  return holes.size();
}

// ------------------------------------------------------------

void BlockSolver::shrink(const CLHEP::HepMatrix& matrix,
                         CLHEP::HepMatrix& solution,
                         const CLHEP::HepVector& result,
                         CLHEP::HepVector& input,
                         const std::vector<int>& where) {
  int offsetRow = 0;
  std::vector<int>::const_iterator whereRows = where.begin();
  // loop over rows
  for (int row = 0; row < matrix.num_row(); ++row) {
    if (row == *whereRows) {
      //          std::cerr << "        DEBUG shr hole found " << std::endl ;
      ++offsetRow;
      ++whereRows;
      continue;
    }
    input[row - offsetRow] = result[row];
    int offsetCol = 0;
    std::vector<int>::const_iterator whereCols = where.begin();
    // loop over columns
    for (int col = 0; col < matrix.num_col(); ++col) {
      if (col == *whereCols) {
        ++offsetCol;
        ++whereCols;
        continue;
      }
      solution[row - offsetRow][col - offsetCol] = matrix[row][col];
    }
  }  // loop over rows
  return;
}

// ------------------------------------------------------------

void BlockSolver::pour(CLHEP::HepVector& result, const CLHEP::HepVector& output, const std::vector<int>& where) {
  std::vector<int>::const_iterator whereCols = where.begin();
  int readingIndex = 0;
  //PG loop over the output crystals
  for (int xtal = 0; xtal < result.num_row(); ++xtal) {
    if (xtal == *whereCols) {
      result[xtal] = 1.;
      ++whereCols;
    } else {
      result[xtal] = output[readingIndex];
      ++readingIndex;
    }
  }  //PG loop over the output crystals

  return;
}