CompressedLinearAlgebra.cpph

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#include "toolbox/multiprecision/CompressedFloatingPointNumbers.h"
 
 
template<int Size>
std::vector<unsigned char> toolbox::multiprecision::compress(const tarch::la::Vector<Size,double>& vector, double maxAbsoluteError) {
  std::vector<unsigned char> result;
  unsigned char bytesForMantissa = findMostAgressiveCompression( vector.data(), Size, maxAbsoluteError );
  result.push_back(bytesForMantissa);
 
  if (bytesForMantissa>0) {
    for (int i=0; i<Size; i++) {
      char     exponent;
      long int mantissa;
      double   error;
      char*    pMantissa = reinterpret_cast<char*>( &(mantissa) );
 
      decompose( vector(i), exponent, mantissa, bytesForMantissa );
 
      result.push_back(exponent);
      for (int j=0; j<bytesForMantissa; j++) {
        result.push_back(pMantissa[j]);
      }
    }
  }
  return result;
}
 
 
template<int Rows, int Cols>
std::vector<unsigned char> toolbox::multiprecision::compress(const tarch::la::Matrix<Rows,Cols,double>& matrix, double maxAbsoluteError) {
  std::vector<unsigned char> result;
  unsigned char bytesForMantissa = findMostAgressiveCompression( matrix.data(), Rows*Cols, maxAbsoluteError );
  result.push_back(bytesForMantissa);
  if (bytesForMantissa>0) {
    for (int row=0; row<Rows; row++)
    for (int col=0; col<Cols; col++) {
      char     exponent;
      long int mantissa;
      double   error;
      char*    pMantissa = reinterpret_cast<char*>( &(mantissa) );
 
      decompose( matrix(row,col), exponent, mantissa, bytesForMantissa );
 
      result.push_back(exponent);
      for (int j=0; j<bytesForMantissa; j++) {
        result.push_back(pMantissa[j]);
      }
    }
  }
  return result;
}
 
 
 
template<int Size>
tarch::la::Vector<Size,double> toolbox::multiprecision::uncompressVector( const std::vector<unsigned char>& stream ) {
  tarch::la::Vector<Size,double> result;
 
  int index = 0;
  unsigned char bytesForMantissa = stream[index]; index++;
 
  for (int i=0; i<Size; i++) {
    if (bytesForMantissa>0) {
      char     exponent;
      long int mantissa;
      char*    pMantissa = reinterpret_cast<char*>( &(mantissa) );
 
      exponent = stream[index]; index++;
      for (int j=0; j<bytesForMantissa; j++) {
        pMantissa[j] = stream[index]; index++;
      }
 
      result(i) = compose( exponent, mantissa, bytesForMantissa );
    }
    else {
      result(i) = 0;
    }
  }
 
  assertionEquals(index,stream.size());
 
  return result;
}
 
 
template<int Rows, int Cols>
tarch::la::Matrix<Rows,Cols,double> toolbox::multiprecision::uncompressMatrix( const std::vector<unsigned char>& stream ) {
  tarch::la::Matrix<Rows,Cols,double> result;
 
  int index = 0;
  unsigned char bytesForMantissa = stream[index]; index++;
 
  for (int row=0; row<Rows; row++)
  for (int col=0; col<Cols; col++) {
    if (bytesForMantissa>0) {
      char     exponent;
      long int mantissa = 0;
      char*    pMantissa = reinterpret_cast<char*>( &(mantissa) );
 
      exponent = stream[index]; index++;
      for (int j=0; j<bytesForMantissa; j++) {
        pMantissa[j] = stream[index]; index++;
      }
 
      result(row,col) = compose( exponent, mantissa, bytesForMantissa );
    }
    else {
      result(row,col) = 0;
    }
  }
 
  assertionEquals(index,stream.size());
 
  return result;
}