---

Matrix.cxx

Go to the documentation of this file.

#include "AtlfastUtils/Matrix.h"
#include <cstddef>
#include <assert.h>
namespace Atlfast{
  Matrix::Matrix(size_t x, size_t y){
    m_d1=x;
    m_d2=y;
    m_v=new valarray<double>(x*y);
  }

  Matrix::Matrix(size_t x, size_t y, double init){
    m_d1=x;
    m_d2=y;
    m_v=new valarray<double>(x*y);
    for(size_t i=0; i<m_d1*m_d2; ++i)  m_v[i]=init;
  }

  double& Matrix::operator()(size_t x, size_t y){
    return column(x)[y];
  }

  double mul(const Cslice_iter<double>& v1, 
             const valarray<double>& v2){
    double res=0;
    for( size_t i=0; i<v2.size(); i++) res+=v1[i]*v2[i];
    return res;
  }

  valarray<double> operator*(const Matrix&m, const valarray<double>&v){
    valarray<double> res(m.dim2());
    for(size_t i=0; i<m.dim2(); i++) res[i]=mul(m.row(i), v);
    return res;
  }

  Matrix& Matrix::operator*=(double d){
    (*m_v) *= d;
    return *this;
  }
  Matrix Matrix::sub(int minRow, int maxRow, 
                     int minCol, int maxCol) const{
    int endRow=maxRow+1;
    int endCol=maxCol+1;

    assert(minRow>=0);
    assert(minCol>=0);
    assert(endRow<=m_d1);
    assert(endCol<=m_d2);

    int nRow=endRow-minRow;
    assert(nRow>0);
    
    int nCol=endCol-minCol;
    assert(nCol>0);

    Matrix m(nRow, nCol);
    int ii=0;
    int jj;
    for(int i = minRow; i<endRow; ++i){
      jj=0;
      for(int j = minCol; j<endCol; ++j) m[ii][jj++]=(*this)[i][j];
      ++ii;
    }
    assert(ii == endRow);
    assert(jj == endCol);
    return m;
  }
  void Matrix::sub(int minRow, int minCol, Matrix& m) const{
    int endRow=minRow+m.m_d1;
    int endCol=minCol+m.m_d2;

    assert(minRow>=0);
    assert(minCol>=0);
    assert(endRow<=m_d1);
    assert(endCol<=m_d2);

    int nRow=endRow-minRow;
    assert(nRow>0);
    
    int nCol=endCol-minCol;
    assert(nCol>0);

    int ii=0;
    int jj;
    for(int i = minRow; i<endRow; ++i){
      jj=0;
      for(int j = minCol; j<endCol; ++j) m[ii][jj++]=(*this)[i][j];
      ++ii;
    }
    assert(ii == endRow);
    assert(jj == endCol);
    return;
  }
}//namespace

---