Glue_cross

Classes

class  glue_cross

Functions

template<typename T1 , typename T2 >
static void glue_cross::apply (Mat< typename T1::elem_type > &out, const Glue< T1, T2, glue_cross > &X)

Function Documentation

template<typename T1 , typename T2 >
void glue_cross::apply ( Mat< typename T1::elem_type > &  out,
const Glue< T1, T2, glue_cross > &  X 
) [inline, static, inherited]

Definition at line 26 of file glue_cross_meat.hpp.

References Glue< T1, T2, glue_type >::A, Glue< T1, T2, glue_type >::B, unwrap< T1 >::M, Mat< eT >::memptr(), Mat< eT >::n_cols, Mat< eT >::n_elem, Mat< eT >::n_rows, and Mat< eT >::set_size().

00027   {
00028   arma_extra_debug_sigprint();
00029   
00030   typedef typename T1::elem_type eT;
00031   
00032   const unwrap<T1> A_tmp(X.A);
00033   const unwrap<T2> B_tmp(X.B);
00034   
00035   const Mat<eT>& A = A_tmp.M;
00036   const Mat<eT>& B = B_tmp.M;
00037   
00038   arma_debug_check( ((A.n_elem != 3) || (B.n_elem != 3)), "cross(): input vectors must have 3 elements" );
00039   
00040   out.set_size(A.n_rows, A.n_cols);
00041   
00042         eT* out_ptr = out.memptr();
00043   const eT* A_ptr   = A.memptr();
00044   const eT* B_ptr   = B.memptr();
00045   
00046   // out_ptr[0] = A_ptr[1]*B_ptr[2] - A_ptr[2]*B_ptr[1];
00047   // out_ptr[1] = A_ptr[2]*B_ptr[0] - A_ptr[0]*B_ptr[2];
00048   // out_ptr[2] = A_ptr[0]*B_ptr[1] - A_ptr[1]*B_ptr[0];
00049   
00050   const eT ax = A_ptr[0];
00051   const eT ay = A_ptr[1];
00052   const eT az = A_ptr[2];
00053   
00054   const eT bx = B_ptr[0];
00055   const eT by = B_ptr[1];
00056   const eT bz = B_ptr[2];
00057   
00058   out_ptr[0] = ay*bz - az*by;
00059   out_ptr[1] = az*bx - ax*bz;
00060   out_ptr[2] = ax*by - ay*bx;
00061   }