Function complexapplyreflectionfromtheright

src/creflections.cpp:266–304

Application of an elementary reflection to a rectangular matrix of size MxN The algorithm post-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 th

     September 30, 1994
*************************************************************************/
void complexapplyreflectionfromtheright(ap::complex_2d_array& c,
     ap::complex tau,
     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 * v
    //
    vm = n2-n1+1;
    for(i = m1; i <= m2; i++)
    {
        t = ap::vdotproduct(&c(i, n1), 1, "N", &v(1), 1, "N", ap::vlen(n1,n2));
        work(i) = t;
    }
    
    //
    // C := C - w * conj(v^T)
    //
    ap::vmove(&v(1), 1, &v(1), 1, "Conj", ap::vlen(1,vm));
    for(i = m1; i <= m2; i++)
    {
        t = work(i)*tau;
        ap::vsub(&c(i, n1), 1, &v(1), 1, "N", ap::vlen(n1,n2), t);
    }
    ap::vmove(&v(1), 1, &v(1), 1, "Conj", ap::vlen(1,vm));
}