Fn_prod

Functions

template<typename T1 >
arma_inline const Op< T1, op_prodprod (const Base< typename T1::elem_type, T1 > &X, const u32 dim=0)
 Delayed product of elements of a matrix along a specified dimension (either rows or columns). The result is stored in a dense matrix that has either one column or one row. For dim = 0, find the sum of each column (i.e. traverse across rows) For dim = 1, find the sum of each row (i.e. traverse across columns) The default is dim = 0. NOTE: this function works differently than in Matlab/Octave.
template<typename eT >
eT prod (const Row< eT > &X)
 Immediate 'product of all values' operation for a row vector.
template<typename eT >
eT prod (const Col< eT > &X)
 Immediate 'product of all values' operation for a column vector.
template<typename T1 >
T1::elem_type prod (const Op< T1, op_prod > &in)
 Immediate 'product of all values' operation, invoked, for example, by: prod(prod(A)).
template<typename T1 >
const Op< Op< T1, op_prod >
, op_prod
prod (const Op< T1, op_prod > &in, const u32 dim)
template<typename eT >
eT prod (const subview_row< eT > &S)
 product of all values of a subview_row
template<typename eT >
eT prod (const subview_col< eT > &S)
 product of all values of a subview_col
template<typename eT >
eT prod (const diagview< eT > &X)
 product of all values of a diagview

Function Documentation

template<typename T1 >
arma_inline const Op<T1, op_prod> prod ( const Base< typename T1::elem_type, T1 > &  X,
const u32  dim = 0 
) [inline]

Delayed product of elements of a matrix along a specified dimension (either rows or columns). The result is stored in a dense matrix that has either one column or one row. For dim = 0, find the sum of each column (i.e. traverse across rows) For dim = 1, find the sum of each row (i.e. traverse across columns) The default is dim = 0. NOTE: this function works differently than in Matlab/Octave.

Definition at line 32 of file fn_prod.hpp.

References Base< elem_type, derived >::get_ref().

00033   {
00034   arma_extra_debug_sigprint();
00035   
00036   return Op<T1, op_prod>(X.get_ref(), dim, 0);
00037   }

template<typename eT >
eT prod ( const Row< eT > &  X  )  [inline]

Immediate 'product of all values' operation for a row vector.

Definition at line 46 of file fn_prod.hpp.

References Mat< eT >::memptr(), and Mat< eT >::n_elem.

00047   {
00048   arma_extra_debug_sigprint();
00049   
00050   arma_debug_check( (X.n_elem < 1), "prod(): given object has no elements" );
00051   
00052   const u32 n_elem = X.n_elem;
00053   const eT* X_mem  = X.memptr();
00054   
00055   eT val = X_mem[0];
00056   
00057   for(u32 i=1; i<n_elem; ++i)
00058     {
00059     val *= X_mem[i];
00060     }
00061   
00062   return val;
00063   }

template<typename eT >
eT prod ( const Col< eT > &  X  )  [inline]

Immediate 'product of all values' operation for a column vector.

Definition at line 72 of file fn_prod.hpp.

References Mat< eT >::memptr(), and Mat< eT >::n_elem.

00073   {
00074   arma_extra_debug_sigprint();
00075   
00076   arma_debug_check( (X.n_elem < 1), "prod(): given object has no elements" );
00077   
00078   const u32 n_elem = X.n_elem;
00079   const eT* X_mem  = X.memptr();
00080   
00081   eT val = X_mem[0];
00082   
00083   for(u32 i=1; i<n_elem; ++i)
00084     {
00085     val *= X_mem[i];
00086     }
00087   
00088   return val;
00089   }

template<typename T1 >
T1::elem_type prod ( const Op< T1, op_prod > &  in  )  [inline]

Immediate 'product of all values' operation, invoked, for example, by: prod(prod(A)).

Definition at line 100 of file fn_prod.hpp.

References unwrap< T1 >::M, Op< T1, op_type >::m, Mat< eT >::memptr(), and Mat< eT >::n_elem.

00101   {
00102   arma_extra_debug_sigprint();
00103   arma_extra_debug_print("prod(): two consecutive prod() calls detected");
00104   
00105   typedef typename T1::elem_type eT;
00106   
00107   const unwrap<T1>   tmp(in.m);
00108   const Mat<eT>& X = tmp.M;
00109   
00110   arma_debug_check( (X.n_elem < 1), "prod(): given object has no elements" );
00111   
00112   const u32 n_elem = X.n_elem;
00113   const eT* X_mem  = X.memptr();
00114   
00115   eT val = X_mem[0];
00116   
00117   for(u32 i=1; i<n_elem; ++i)
00118     {
00119     val *= X_mem[i];
00120     }
00121   
00122   return val;
00123   }

template<typename T1 >
const Op<Op<T1, op_prod>, op_prod> prod ( const Op< T1, op_prod > &  in,
const u32  dim 
) [inline]

Definition at line 130 of file fn_prod.hpp.

00131   {
00132   arma_extra_debug_sigprint();
00133   
00134   return Op<Op<T1, op_prod>, op_prod>(in, dim, 0);
00135   }

template<typename eT >
eT prod ( const subview_row< eT > &  S  )  [inline]

product of all values of a subview_row

Definition at line 143 of file fn_prod.hpp.

References Mat< eT >::at(), subview< eT >::aux_col1, subview< eT >::aux_col2, subview< eT >::aux_row1, subview< eT >::m, and subview< eT >::n_elem.

00144   {
00145   arma_extra_debug_sigprint();
00146   
00147   arma_debug_check( (S.n_elem < 1), "prod(): given object has no elements" );
00148   
00149   const Mat<eT>& X = S.m;
00150   
00151   const u32 row       = S.aux_row1;
00152   const u32 start_col = S.aux_col1;
00153   const u32 end_col   = S.aux_col2;
00154   
00155   eT val = X.at(row,start_col);
00156   
00157   for(u32 col=start_col+1; col<=end_col; ++col)
00158     {
00159     val *= X.at(row,col);
00160     }
00161   
00162   return val;
00163   }

template<typename eT >
eT prod ( const subview_col< eT > &  S  )  [inline]

product of all values of a subview_col

Definition at line 171 of file fn_prod.hpp.

References subview< eT >::colptr(), subview< eT >::n_elem, and subview< eT >::n_rows.

00172   {
00173   arma_extra_debug_sigprint();
00174   
00175   arma_debug_check( (S.n_elem < 1), "prod(): given object has no elements" );
00176   
00177   const eT* S_colptr = S.colptr(0);
00178   const u32 n_rows   = S.n_rows;
00179   
00180   eT val = S_colptr[0];
00181   
00182   for(u32 row=1; row<n_rows; ++row)
00183     {
00184     val *= S_colptr[row];
00185     }
00186   
00187   return val;
00188   }

template<typename eT >
eT prod ( const diagview< eT > &  X  )  [inline]

product of all values of a diagview

Definition at line 196 of file fn_prod.hpp.

References diagview< eT >::n_elem.

00197   {
00198   arma_extra_debug_sigprint();
00199   
00200   arma_debug_check( (X.n_elem < 1), "prod(): given object has no elements" );
00201   
00202   const u32 n_elem = X.n_elem;
00203   
00204   eT val = X[0];
00205   
00206   for(u32 i=1; i<n_elem; ++i)
00207     {
00208     val *= X[i];
00209     }
00210   
00211   return val;
00212   }