rwupdt.h
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00001 namespace Eigen { 
00002 
00003 namespace internal {
00004 
00005 template <typename Scalar>
00006 void rwupdt(
00007         Matrix< Scalar, Dynamic, Dynamic >  &r,
00008         const Matrix< Scalar, Dynamic, 1>  &w,
00009         Matrix< Scalar, Dynamic, 1>  &b,
00010         Scalar alpha)
00011 {
00012     typedef DenseIndex Index;
00013 
00014     const Index n = r.cols();
00015     assert(r.rows()>=n);
00016     std::vector<JacobiRotation<Scalar> > givens(n);
00017 
00018     /* Local variables */
00019     Scalar temp, rowj;
00020 
00021     /* Function Body */
00022     for (Index j = 0; j < n; ++j) {
00023         rowj = w[j];
00024 
00025         /* apply the previous transformations to */
00026         /* r(i,j), i=0,1,...,j-1, and to w(j). */
00027         for (Index i = 0; i < j; ++i) {
00028             temp = givens[i].c() * r(i,j) + givens[i].s() * rowj;
00029             rowj = -givens[i].s() * r(i,j) + givens[i].c() * rowj;
00030             r(i,j) = temp;
00031         }
00032 
00033         /* determine a givens rotation which eliminates w(j). */
00034         givens[j].makeGivens(-r(j,j), rowj);
00035 
00036         if (rowj == 0.)
00037             continue; // givens[j] is identity
00038 
00039         /* apply the current transformation to r(j,j), b(j), and alpha. */
00040         r(j,j) = givens[j].c() * r(j,j) + givens[j].s() * rowj;
00041         temp = givens[j].c() * b[j] + givens[j].s() * alpha;
00042         alpha = -givens[j].s() * b[j] + givens[j].c() * alpha;
00043         b[j] = temp;
00044     }
00045 }
00046 
00047 } // end namespace internal
00048 
00049 } // end namespace Eigen


win_eigen
Author(s): Daniel Stonier
autogenerated on Mon Oct 6 2014 12:25:49