Functions | |
template<typename T1 > | |
u32 | rank (const Base< typename T1::elem_type, T1 > &X, typename T1::pod_type tol=0.0) |
u32 rank | ( | const Base< typename T1::elem_type, T1 > & | X, | |
typename T1::pod_type | tol = 0.0 | |||
) | [inline] |
Definition at line 26 of file fn_rank.hpp.
References arma_print(), op_eps::direct_eps(), Base< elem_type, derived >::get_ref(), max(), Mat< eT >::memptr(), Mat< eT >::n_elem, and auxlib::svd().
00027 { 00028 arma_extra_debug_sigprint(); 00029 00030 typedef typename T1::elem_type eT; 00031 typedef typename T1::pod_type T; 00032 00033 const unwrap<T1> tmp(X.get_ref()); 00034 const Mat<eT>& A = tmp.M; 00035 00036 Col<T> s; 00037 const bool status = auxlib::svd(s, A); 00038 00039 if(status == true) 00040 { 00041 if(tol == T(0)) 00042 { 00043 tol = (std::max)(A.n_rows, A.n_cols) * op_eps::direct_eps(max(s)); 00044 } 00045 00046 // count non zero valued elements in s 00047 00048 const T* s_mem = s.memptr(); 00049 const u32 n_elem = s.n_elem; 00050 u32 count = 0; 00051 00052 for(u32 i=0; i<n_elem; ++i) 00053 { 00054 if(s_mem[i] > tol) 00055 { 00056 ++count; 00057 } 00058 } 00059 00060 return count; 00061 } 00062 else 00063 { 00064 arma_print("rank(): singular value decomposition failed"); 00065 return u32(0); 00066 } 00067 00068 }