Op_diagmat

//! More...

Classes
class	op_diagmat
Functions
template<typename T1 >
static void	op_diagmat::apply (Mat< typename T1::elem_type > &out, const Op< T1, op_diagmat > &X)

---

Detailed Description

//!

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Function Documentation

template<typename T1 >

void op_diagmat::apply	(	Mat< typename T1::elem_type > &	out,
		const Op< T1, op_diagmat > &	X
	)			[inline, static, inherited]

Definition at line 25 of file op_diagmat_meat.hpp.

References Mat< eT >::at(), Mat< eT >::is_square(), Mat< eT >::is_vec(), unwrap< T1 >::M, Op< T1, op_type >::m, podarray< eT >::memptr(), Mat< eT >::memptr(), Mat< eT >::n_elem, Mat< eT >::n_rows, Mat< eT >::set_size(), and Mat< eT >::zeros().

  {
  arma_extra_debug_sigprint();
  
  typedef typename T1::elem_type eT;
  
  const unwrap<T1>   tmp(X.m);
  const Mat<eT>& A = tmp.M;
  
  if(A.is_vec() == true)
    {
    // generate a diagonal matrix out of a vector
    
    const u32 N     = A.n_elem;
    const eT* A_mem = A.memptr();
    
    if(&out != &A)
      {
      // no aliasing
      out.zeros(N,N);
      
      for(u32 i=0; i<N; ++i)
        {
        out.at(i,i) = A_mem[i];
        }
      }
    else
      {
      // aliasing
      
      const podarray<eT> tmp(A_mem, N);
      
      const eT* tmp_mem = tmp.memptr();
      
      out.zeros(N,N);
      
      for(u32 i=0; i<N; ++i)
        {
        out.at(i,i) = tmp_mem[i];
        }
      }
    }
  else
    {
    // generate a diagonal matrix out of a matrix
    
    arma_debug_check( (A.is_square() == false), "diagmat(): given matrix is not square" );
    
    const u32 N = A.n_rows;
    
    out.set_size(N,N);
    
    for(u32 col=0; col<N; ++col)
      {
      for(u32 row=0;     row<col; ++row) { out.at(row,col) = eT(0); }
      
      out.at(col,col) = A.at(col,col);
      
      for(u32 row=col+1; row<N;   ++row) { out.at(row,col) = eT(0); }
      }
    }
  }