comparison armadillo-2.4.4/include/armadillo_bits/fn_misc.hpp @ 0:8b6102e2a9b0

Armadillo Library

+// Copyright (C) 2008-2011 NICTA (www.nicta.com.au)
+// Copyright (C) 2008-2011 Conrad Sanderson
+// 
+// This file is part of the Armadillo C++ library.
+// It is provided without any warranty of fitness
+// for any purpose. You can redistribute this file
+// and/or modify it under the terms of the GNU
+// Lesser General Public License (LGPL) as published
+// by the Free Software Foundation, either version 3
+// of the License or (at your option) any later version.
+// (see http://www.opensource.org/licenses for more info)
+
+
+//! \addtogroup fn_misc
+//! @{
+
+
+
+//! \brief
+//! Generate a vector with 'num' elements.
+//! The values of the elements linearly increase from 'start' upto (and including) 'end'.
+
+template<typename vec_type>
+inline
+vec_type
+linspace
+  (
+  const typename vec_type::pod_type start,
+  const typename vec_type::pod_type end,
+  const uword num = 100u,
+  const typename arma_Mat_Col_Row_only<vec_type>::result* junk = 0
+  )
+  {
+  arma_extra_debug_sigprint();
+  arma_ignore(junk);
+  
+  typedef typename vec_type::elem_type eT;
+  typedef typename vec_type::pod_type   T;
+  
+  vec_type x;
+    
+  if(num >= 2)
+    {
+    x.set_size(num);
+    
+    eT* x_mem = x.memptr();
+    
+    const uword num_m1 = num - 1;
+    
+    if(is_non_integral<T>::value == true)
+      {
+      const T delta = (end-start)/T(num_m1);
+      
+      for(uword i=0; i<num_m1; ++i)
+        {
+        x_mem[i] = eT(start + i*delta);
+        }
+      
+      x_mem[num_m1] = eT(end);
+      }
+    else
+      {
+      const double delta = (end >= start) ? double(end-start)/double(num_m1) : -double(start-end)/double(num_m1);
+      
+      for(uword i=0; i<num_m1; ++i)
+        {
+        x_mem[i] = eT(double(start) + i*delta);
+        }
+      
+      x_mem[num_m1] = eT(end);
+      }
+    
+    return x;
+    }
+  else
+    {
+    x.set_size(1);
+    
+    x[0] = eT(end);
+    }
+  
+  return x;
+  }
+
+
+
+inline
+mat
+linspace(const double start, const double end, const uword num = 100u)
+  {
+  arma_extra_debug_sigprint();
+  return linspace<mat>(start, end, num);
+  }
+
+
+
+//
+// log_add
+
+template<typename eT>
+inline
+typename arma_float_only<eT>::result
+log_add(eT log_a, eT log_b)
+  {
+  if(log_a < log_b)
+    {
+    std::swap(log_a, log_b);
+    }
+  
+  const eT negdelta = log_b - log_a;
+  
+  if( (negdelta < Math<eT>::log_min()) || (arma_isfinite(negdelta) == false) )
+    {
+    return log_a;
+    }
+  else
+    {
+    #if defined(ARMA_HAVE_LOG1P)
+      return (log_a + log1p(std::exp(negdelta)));
+    #else
+      return (log_a + std::log(1.0 + std::exp(negdelta)));
+    #endif
+    }
+  }
+
+
+
+template<typename eT>
+arma_inline
+arma_warn_unused
+bool
+is_finite(const eT x, const typename arma_scalar_only<eT>::result* junk = 0)
+  {
+  arma_ignore(junk);
+  
+  return arma_isfinite(x);
+  }
+
+
+
+template<typename T1>
+inline
+arma_warn_unused
+bool
+is_finite(const Base<typename T1::elem_type,T1>& X)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename T1::elem_type eT;
+  
+  const unwrap<T1>   tmp(X.get_ref());
+  const Mat<eT>& A = tmp.M;
+  
+  return A.is_finite();
+  }
+
+
+
+template<typename T1>
+inline
+arma_warn_unused
+bool
+is_finite(const BaseCube<typename T1::elem_type,T1>& X)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename T1::elem_type eT;
+  
+  const unwrap_cube<T1> tmp(X.get_ref());
+  const Cube<eT>& A =   tmp.M;
+  
+  return A.is_finite();
+  }
+
+
+
+template<typename T1>
+arma_inline
+Op<T1, op_sympd>
+sympd(const Base<typename T1::elem_type,T1>& X)
+  {
+  arma_extra_debug_sigprint();
+  
+  return Op<T1, op_sympd>(X.get_ref());
+  }
+
+
+
+//! @}