macaulayMatrixStats()

auto F4GB::macaulayMatrixStats ( ) const

private

Definition at line 515 of file f4.cpp.

{
  // Want:
  //  sizes of A, B, C, D.
  //  number of elements in each part.
  // loop through the rows, and for each row, determine: in A or C?
  //   loop through elements in a row: for each, determine: in A/C or B/D
 
  MacaulayMatrixStats stats;
 
  // look at 'mat', determine number of rows, cols, etc.
  long nrows = mat->rows.size();
  long ncols = mat->columns.size();
  for (long i=0; i<nrows; ++i)
    {
      bool is_pivot = is_pivot_row(i);
      if (is_pivot)
        ++stats.mTopAndLeft;
 
      auto& r = mat->rows[i];
      for (long j=0; j < r.len; ++j)
          {
            auto c = r.comps[j];
            bool is_left = mat->columns[c].head >= 0;
            if (is_pivot and is_left) ++stats.mAEntries;
            if (is_pivot and not is_left) ++stats.mBEntries;
            if (not is_pivot and is_left) ++stats.mCEntries;
            if (not is_pivot and not is_left) ++stats.mDEntries;
          }
    }
 
  stats.mAEntries -= stats.mTopAndLeft;
  stats.mBottom = nrows - stats.mTopAndLeft;
  stats.mRight = ncols - stats.mTopAndLeft;
 
  stats.display();
  return stats;
}

References F4GB::MacaulayMatrixStats::display(), is_pivot_row(), F4GB::MacaulayMatrixStats::mAEntries, mat, F4GB::MacaulayMatrixStats::mBEntries, F4GB::MacaulayMatrixStats::mBottom, F4GB::MacaulayMatrixStats::mCEntries, F4GB::MacaulayMatrixStats::mDEntries, F4GB::MacaulayMatrixStats::mRight, and F4GB::MacaulayMatrixStats::mTopAndLeft.

Referenced by make_matrix().