//! More...
Classes | |
class | op_prod |
Class for finding products of values in a matrix (e.g. along rows or columns). More... | |
Functions | |
template<typename T1 > | |
static void | op_prod::apply (Mat< typename T1::elem_type > &out, const Op< T1, op_prod > &in) |
//! Immediate 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. //! See the prod() function for more details. |
//!
void op_prod::apply | ( | Mat< typename T1::elem_type > & | out, | |
const Op< T1, op_prod > & | in | |||
) | [inline, static, inherited] |
//! Immediate 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. //! See the prod() function for more details.
Definition at line 27 of file op_prod_meat.hpp.
References Mat< eT >::at(), Op< T1, op_type >::aux_u32_a, Mat< eT >::colptr(), unwrap_check< T1 >::M, Op< T1, op_type >::m, Mat< eT >::n_cols, Mat< eT >::n_elem, Mat< eT >::n_rows, and Mat< eT >::set_size().
{ arma_extra_debug_sigprint(); typedef typename T1::elem_type eT; const u32 dim = in.aux_u32_a; arma_debug_check( (dim > 1), "prod(): incorrect usage. dim must be 0 or 1"); const unwrap_check<T1> tmp(in.m, out); const Mat<eT>& X = tmp.M; arma_debug_check( (X.n_elem < 1), "prod(): give object has no elements"); if(dim == 0) // traverse across rows (i.e. find the product in each column) { out.set_size(1, X.n_cols); for(u32 col=0; col<X.n_cols; ++col) { const eT* X_colptr = X.colptr(col); eT val = X_colptr[0]; for(u32 row=1; row < X.n_rows; ++row) { val *= X_colptr[row]; } out.at(0,col) = val; } } else // traverse across columns (i.e. find the product in each row) { out.set_size(X.n_rows, 1); for(u32 row=0; row < X.n_rows; ++row) { eT val = X.at(row,0); for(u32 col=1; col < X.n_cols; ++col) { val *= X.at(row,col); } out.at(row,0) = val; } } }