Chris@49: // Copyright (C) 2008-2011 NICTA (www.nicta.com.au)
Chris@49: // Copyright (C) 2008-2011 Conrad Sanderson
Chris@49: // 
Chris@49: // This Source Code Form is subject to the terms of the Mozilla Public
Chris@49: // License, v. 2.0. If a copy of the MPL was not distributed with this
Chris@49: // file, You can obtain one at http://mozilla.org/MPL/2.0/.
Chris@49: 
Chris@49: 
Chris@49: //! \addtogroup fn_misc
Chris@49: //! @{
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: //! \brief
Chris@49: //! Generate a vector with 'num' elements.
Chris@49: //! The values of the elements linearly increase from 'start' upto (and including) 'end'.
Chris@49: 
Chris@49: template<typename vec_type>
Chris@49: inline
Chris@49: vec_type
Chris@49: linspace
Chris@49:   (
Chris@49:   const typename vec_type::pod_type start,
Chris@49:   const typename vec_type::pod_type end,
Chris@49:   const uword num = 100u,
Chris@49:   const typename arma_Mat_Col_Row_only<vec_type>::result* junk = 0
Chris@49:   )
Chris@49:   {
Chris@49:   arma_extra_debug_sigprint();
Chris@49:   arma_ignore(junk);
Chris@49:   
Chris@49:   typedef typename vec_type::elem_type eT;
Chris@49:   typedef typename vec_type::pod_type   T;
Chris@49:   
Chris@49:   vec_type x;
Chris@49:     
Chris@49:   if(num >= 2)
Chris@49:     {
Chris@49:     x.set_size(num);
Chris@49:     
Chris@49:     eT* x_mem = x.memptr();
Chris@49:     
Chris@49:     const uword num_m1 = num - 1;
Chris@49:     
Chris@49:     if(is_non_integral<T>::value == true)
Chris@49:       {
Chris@49:       const T delta = (end-start)/T(num_m1);
Chris@49:       
Chris@49:       for(uword i=0; i<num_m1; ++i)
Chris@49:         {
Chris@49:         x_mem[i] = eT(start + i*delta);
Chris@49:         }
Chris@49:       
Chris@49:       x_mem[num_m1] = eT(end);
Chris@49:       }
Chris@49:     else
Chris@49:       {
Chris@49:       const double delta = (end >= start) ? double(end-start)/double(num_m1) : -double(start-end)/double(num_m1);
Chris@49:       
Chris@49:       for(uword i=0; i<num_m1; ++i)
Chris@49:         {
Chris@49:         x_mem[i] = eT(double(start) + i*delta);
Chris@49:         }
Chris@49:       
Chris@49:       x_mem[num_m1] = eT(end);
Chris@49:       }
Chris@49:     
Chris@49:     return x;
Chris@49:     }
Chris@49:   else
Chris@49:     {
Chris@49:     x.set_size(1);
Chris@49:     
Chris@49:     x[0] = eT(end);
Chris@49:     }
Chris@49:   
Chris@49:   return x;
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: inline
Chris@49: mat
Chris@49: linspace(const double start, const double end, const uword num = 100u)
Chris@49:   {
Chris@49:   arma_extra_debug_sigprint();
Chris@49:   return linspace<mat>(start, end, num);
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: //
Chris@49: // log_exp_add
Chris@49: 
Chris@49: template<typename eT>
Chris@49: inline
Chris@49: typename arma_real_only<eT>::result
Chris@49: log_add_exp(eT log_a, eT log_b)
Chris@49:   {
Chris@49:   if(log_a < log_b)
Chris@49:     {
Chris@49:     std::swap(log_a, log_b);
Chris@49:     }
Chris@49:   
Chris@49:   const eT negdelta = log_b - log_a;
Chris@49:   
Chris@49:   if( (negdelta < Datum<eT>::log_min) || (arma_isfinite(negdelta) == false) )
Chris@49:     {
Chris@49:     return log_a;
Chris@49:     }
Chris@49:   else
Chris@49:     {
Chris@49:     #if defined(ARMA_HAVE_LOG1P)
Chris@49:       return (log_a + log1p(std::exp(negdelta)));
Chris@49:     #else
Chris@49:       return (log_a + std::log(1.0 + std::exp(negdelta)));
Chris@49:     #endif
Chris@49:     }
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: // for compatibility with earlier versions
Chris@49: template<typename eT>
Chris@49: inline
Chris@49: typename arma_real_only<eT>::result
Chris@49: log_add(eT log_a, eT log_b)
Chris@49:   {
Chris@49:   return log_add_exp(log_a, log_b);
Chris@49:   }
Chris@49:   
Chris@49: 
Chris@49: 
Chris@49: template<typename eT>
Chris@49: arma_inline
Chris@49: arma_warn_unused
Chris@49: bool
Chris@49: is_finite(const eT x, const typename arma_scalar_only<eT>::result* junk = 0)
Chris@49:   {
Chris@49:   arma_ignore(junk);
Chris@49:   
Chris@49:   return arma_isfinite(x);
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename T1>
Chris@49: inline
Chris@49: arma_warn_unused
Chris@49: bool
Chris@49: is_finite(const Base<typename T1::elem_type,T1>& X)
Chris@49:   {
Chris@49:   arma_extra_debug_sigprint();
Chris@49:   
Chris@49:   typedef typename T1::elem_type eT;
Chris@49:   
Chris@49:   const unwrap<T1>   tmp(X.get_ref());
Chris@49:   const Mat<eT>& A = tmp.M;
Chris@49:   
Chris@49:   return A.is_finite();
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename T1>
Chris@49: inline
Chris@49: arma_warn_unused
Chris@49: bool
Chris@49: is_finite(const BaseCube<typename T1::elem_type,T1>& X)
Chris@49:   {
Chris@49:   arma_extra_debug_sigprint();
Chris@49:   
Chris@49:   typedef typename T1::elem_type eT;
Chris@49:   
Chris@49:   const unwrap_cube<T1> tmp(X.get_ref());
Chris@49:   const Cube<eT>& A =   tmp.M;
Chris@49:   
Chris@49:   return A.is_finite();
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename T1>
Chris@49: arma_inline
Chris@49: Op<T1, op_sympd>
Chris@49: sympd(const Base<typename T1::elem_type,T1>& X)
Chris@49:   {
Chris@49:   arma_extra_debug_sigprint();
Chris@49:   
Chris@49:   return Op<T1, op_sympd>(X.get_ref());
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: template<typename eT>
Chris@49: inline
Chris@49: void
Chris@49: swap(Mat<eT>& A, Mat<eT>& B)
Chris@49:   {
Chris@49:   arma_extra_debug_sigprint();
Chris@49:   
Chris@49:   const uword A_mem_state = A.mem_state;
Chris@49:   
Chris@49:   if( (A.vec_state == B.vec_state) && (A_mem_state == B.mem_state) && ((A_mem_state == 0) || (A_mem_state == 3)) )
Chris@49:     {
Chris@49:     A.swap(B);
Chris@49:     }
Chris@49:   else
Chris@49:     {
Chris@49:     if(A.n_elem <= B.n_elem)
Chris@49:       {
Chris@49:       Mat<eT> C = A;
Chris@49:       
Chris@49:       A.steal_mem(B);
Chris@49:       B.steal_mem(C);
Chris@49:       }
Chris@49:     else
Chris@49:       {
Chris@49:       Mat<eT> C = B;
Chris@49:       
Chris@49:       B.steal_mem(A);
Chris@49:       A.steal_mem(C);
Chris@49:       }
Chris@49:     }
Chris@49:   }
Chris@49: 
Chris@49: 
Chris@49: 
Chris@49: //! @}