src/work/alpar/matrix.cc
author alpar
Wed, 16 Feb 2005 16:17:30 +0000
changeset 1151 b217fc69f913
permissions -rw-r--r--
Several changes in the docs.
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#include <lemon/time_measure.h>
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#include <vector>
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template<class T>
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class Matrix 
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{
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public:
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  int m,n;
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  std::vector<T> values;
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  Matrix(int _m, int _n) : m(_m), n(_n), values(n*m) {}
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  typename std::vector<T>::reference operator()(int i, int j)
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  { return values[i*n+j];}
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  class Row 
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  {
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  public:
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    Matrix<T> &mat;
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    int row;
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    Row(Matrix<T> &_mat,int _row) : mat(_mat), row(_row) {}
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    typename std::vector<T>::reference operator()(int j)
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    { return mat.values[row*mat.n+j];}
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  };
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  class Column 
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  {
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  public:
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    Matrix<T> &mat;
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    int col;
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    Column(Matrix<T> &_mat,int _col) : mat(_mat), col(_col) {}
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    typename std::vector<T>::reference operator[](int i)
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    { return mat.values[i*mat.n+col];}
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  };
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  Row operator[](int i) { return Row(*this,i); }
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  Column operator()(int j) { return Column(*this,j); }
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};
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main() 
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{
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  const int COUNT=1000000;
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  const int SIZE=100;
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  Matrix<int> A(SIZE,SIZE);
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  for(int i=0;i<SIZE;i++) for(int j=0;j<SIZE;j++) A(i,j)=i+j;
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  int s=0;
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  lemon::Timer T;
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  for(int c=0;c<COUNT;c++) {
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    for(int i=0;i<SIZE;i++) for(int j=0;j<SIZE;j++) s+=A[i](j);
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  }
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  std::cout << "A[i](j): " << T << ' ' << s <<'\n';
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  s=0;
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  T.reset();
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  for(int c=0;c<COUNT;c++) {
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    for(int i=0;i<SIZE;i++) for(int j=0;j<SIZE;j++) s+=A(i,j);
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  }
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  std::cout << "A(i,j): " << T << ' ' << s << '\n';
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  s=0;
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  T.reset();
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  for(int c=0;c<COUNT;c++) {
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    for(int i=0;i<SIZE;i++) for(int j=0;j<SIZE;j++) s+=A(j)[i];
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  }
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  std::cout << "A(j)[i]: " << T << ' ' << s << '\n';
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  s=0;
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  T.reset();
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  for(int c=0;c<COUNT;c++) {
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    for(int i=0;i<SIZE;i++) for(int j=0;j<SIZE;j++) s+=A(i,j);
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  }
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  std::cout << "A(j,i): " << T << ' ' << s << "\n\n";
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  return 0;
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}