Fn_solve


Functions

template<typename eT , typename T1 , typename T2 >
bool solve (Mat< eT > &X, const Base< eT, T1 > &A_in, const Base< eT, T2 > &B_in)
 Solve a system of linear equations, i.e., A*X = B, where X is unknown. For a square matrix A, this function is conceptually the same as X = inv(A)*B, but is done more efficiently. The number of rows in A and B must be the same. B can be either a column vector or a matrix. This function will also try to provide approximate solutions to under-determined as well as over-determined systems (non-square A matrices).
template<typename eT , typename T1 , typename T2 >
Mat< eT > solve (const Base< eT, T1 > &A_in, const Base< eT, T2 > &B_in)

Function Documentation

template<typename eT , typename T1 , typename T2 >
bool solve ( Mat< eT > &  X,
const Base< eT, T1 > &  A_in,
const Base< eT, T2 > &  B_in 
) [inline]

Solve a system of linear equations, i.e., A*X = B, where X is unknown. For a square matrix A, this function is conceptually the same as X = inv(A)*B, but is done more efficiently. The number of rows in A and B must be the same. B can be either a column vector or a matrix. This function will also try to provide approximate solutions to under-determined as well as over-determined systems (non-square A matrices).

Definition at line 32 of file fn_solve.hpp.

References Base< elem_type, derived >::get_ref(), Mat< eT >::n_rows, auxlib::solve(), auxlib::solve_od(), and auxlib::solve_ud().

Referenced by solve().

00033   {
00034   arma_extra_debug_sigprint();
00035   
00036   const unwrap<T1> tmp1(A_in.get_ref());
00037   const unwrap<T2> tmp2(B_in.get_ref());
00038   
00039   const Mat<eT>& A = tmp1.M;
00040   const Mat<eT>& B = tmp2.M;
00041   
00042   arma_debug_check( (A.n_rows != B.n_rows), "solve(): number of rows in A and B must be the same" );
00043   
00044   if(A.n_rows == A.n_cols)
00045     {
00046     return auxlib::solve(X, A, B);
00047     }
00048   else
00049   if(A.n_rows > A.n_cols)
00050     {
00051     arma_extra_debug_print("solve(): detected over-determined system");
00052     return auxlib::solve_od(X, A, B);
00053     }
00054   else
00055     {
00056     arma_extra_debug_print("solve(): detected under-determined system");
00057     return auxlib::solve_ud(X, A, B);
00058     }
00059   }

template<typename eT , typename T1 , typename T2 >
Mat<eT> solve ( const Base< eT, T1 > &  A_in,
const Base< eT, T2 > &  B_in 
) [inline]

Definition at line 66 of file fn_solve.hpp.

References arma_print(), and solve().

00067   {
00068   arma_extra_debug_sigprint();
00069   
00070   Mat<eT> X;
00071   bool info = solve(X, A_in, B_in);
00072   
00073   if(info == false)
00074     {
00075     arma_print("solve(): solution not found");
00076     }
00077   
00078   return X;
00079   }