Function complexapplyreflectionfromtheleft

src/creflections.cpp:195–235

Application of an elementary reflection to a rectangular matrix of size MxN The algorithm pre-multiplies the matrix by an elementary reflection transformation which is given by column V and scalar Tau (see the description of the GenerateReflection). Not the whole matrix but only a part of it is transformed (rows from M1 to M2, columns from N1 to N2). Only the elements of this s

     September 30, 1994
*************************************************************************/
void complexapplyreflectionfromtheleft(ap::complex_2d_array& c,
     ap::complex tau,
     const ap::complex_1d_array& v,
     int m1,
     int m2,
     int n1,
     int n2,
     ap::complex_1d_array& work)
{
    ap::complex t;
    int i;
    int vm;

    if( tau==0||n1>n2||m1>m2 )
    {
        return;
    }
    
    //
    // w := C^T * conj(v)
    //
    vm = m2-m1+1;
    for(i = n1; i <= n2; i++)
    {
        work(i) = 0;
    }
    for(i = m1; i <= m2; i++)
    {
        t = ap::conj(v(i+1-m1));
        ap::vadd(&work(n1), 1, &c(i, n1), 1, "N", ap::vlen(n1,n2), t);
    }
    
    //
    // C := C - tau * v * w^T
    //
    for(i = m1; i <= m2; i++)
    {
        t = v(i-m1+1)*tau;
        ap::vsub(&c(i, n1), 1, &work(n1), 1, "N", ap::vlen(n1,n2), t);
    }
}


/*************************************************************************