comparison armadillo-2.4.4/include/armadillo_bits/op_min_meat.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 op_min
+//! @{
+
+
+
+template<typename eT>
+arma_pure
+inline 
+eT
+op_min::direct_min(const eT* const X, const uword n_elem)
+  {
+  arma_extra_debug_sigprint();
+  
+  eT min_val = priv::most_pos<eT>();
+  
+  uword i,j;
+  
+  for(i=0, j=1; j<n_elem; i+=2, j+=2)
+    {
+    const eT X_i = X[i];
+    const eT X_j = X[j];
+    
+    if(X_i < min_val)
+      {
+      min_val = X_i;
+      }
+    
+    if(X_j < min_val)
+      {
+      min_val = X_j;
+      }
+    }
+  
+  
+  if(i < n_elem)
+    {
+    const eT X_i = X[i];
+    
+    if(X_i < min_val)
+      {
+      min_val = X_i;
+      }
+    }
+  
+  return min_val;
+  }
+
+
+
+template<typename eT>
+inline 
+eT
+op_min::direct_min(const eT* const X, const uword n_elem, uword& index_of_min_val)
+  {
+  arma_extra_debug_sigprint();
+  
+  eT min_val = priv::most_pos<eT>();
+  
+  uword best_index = 0;
+  
+  uword i,j;
+  
+  for(i=0, j=1; j<n_elem; i+=2, j+=2)
+    {
+    const eT X_i = X[i];
+    const eT X_j = X[j];
+    
+    if(X_i < min_val)
+      {
+      min_val    = X_i;
+      best_index = i;
+      }
+    
+    if(X_j < min_val)
+      {
+      min_val    = X_j;
+      best_index = j;
+      }
+    }
+  
+  
+  if(i < n_elem)
+    {
+    const eT X_i = X[i];
+    
+    if(X_i < min_val)
+      {
+      min_val    = X_i;
+      best_index = i;
+      }
+    }
+  
+  index_of_min_val = best_index;
+  
+  return min_val;
+  }  
+
+
+
+template<typename eT>
+inline 
+eT
+op_min::direct_min(const Mat<eT>& X, const uword row)
+  {
+  arma_extra_debug_sigprint();
+  
+  const uword X_n_cols = X.n_cols;
+  
+  eT min_val = priv::most_pos<eT>();
+  
+  for(uword col=0; col<X_n_cols; ++col)
+    {
+    const eT tmp_val = X.at(row,col);
+    
+    if(tmp_val < min_val)
+      {
+      min_val = tmp_val;
+      }
+    }
+  
+  return min_val;
+  }
+
+
+
+template<typename eT>
+inline 
+eT
+op_min::direct_min(const subview<eT>& X)
+  {
+  arma_extra_debug_sigprint();
+  
+  const uword X_n_elem = X.n_elem;
+  
+  eT min_val = priv::most_pos<eT>();
+  
+  for(uword i=0; i<X_n_elem; ++i)
+    {
+    eT tmp_val = X[i];
+    
+    if(tmp_val < min_val)
+      {
+      min_val = tmp_val;
+      }
+    }
+  
+  return min_val;
+  }
+
+
+
+template<typename eT>
+inline 
+eT
+op_min::direct_min(const diagview<eT>& X)
+  {
+  arma_extra_debug_sigprint();
+  
+  const uword X_n_elem = X.n_elem;
+  
+  eT min_val = priv::most_pos<eT>();;
+  
+  for(uword i=0; i<X_n_elem; ++i)
+    {
+    eT tmp_val = X[i];
+    
+    if(tmp_val < min_val)
+      {
+      min_val = tmp_val;
+      }
+    }
+  
+  return min_val;
+  }
+
+
+
+//! \brief
+//! For each row or for each column, find the minimum value.
+//! The result is stored in a dense matrix that has either one column or one row.
+//! The dimension, for which the minima are found, is set via the min() function.
+template<typename T1>
+inline void op_min::apply(Mat<typename T1::elem_type>& out, const Op<T1,op_min>& in)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename T1::elem_type eT;
+  
+  const unwrap_check<T1> tmp(in.m, out);
+  const Mat<eT>&     X = tmp.M;
+  
+  const uword dim = in.aux_uword_a;
+  arma_debug_check( (dim > 1), "min(): incorrect usage. dim must be 0 or 1");
+  
+  const uword X_n_rows = X.n_rows;
+  const uword X_n_cols = X.n_cols;
+  
+  if(dim == 0)  // min in each column
+    {
+    arma_extra_debug_print("op_min::apply(), dim = 0");
+    
+    arma_debug_check( (X_n_rows == 0), "min(): given object has zero rows" );
+
+    out.set_size(1, X_n_cols);
+    
+    eT* out_mem = out.memptr();
+    
+    for(uword col=0; col<X_n_cols; ++col)
+      {
+      out_mem[col] = op_min::direct_min( X.colptr(col), X_n_rows );
+      }
+    }
+  else
+  if(dim == 1)  // min in each row
+    {
+    arma_extra_debug_print("op_min::apply(), dim = 1");
+    
+    arma_debug_check( (X_n_cols == 0), "min(): given object has zero columns" );
+
+    out.set_size(X_n_rows, 1);
+    
+    eT* out_mem = out.memptr();
+    
+    for(uword row=0; row<X_n_rows; ++row)
+      {
+      out_mem[row] = op_min::direct_min( X, row );
+      }
+    }
+  }
+
+
+
+template<typename T>
+inline 
+std::complex<T>
+op_min::direct_min(const std::complex<T>* const X, const uword n_elem)
+  {
+  arma_extra_debug_sigprint();
+  
+  uword index   = 0;
+  T   min_val = priv::most_pos<T>();
+  
+  for(uword i=0; i<n_elem; ++i)
+    {
+    const T tmp_val = std::abs(X[i]);
+    
+    if(tmp_val < min_val)
+      {
+      min_val = tmp_val;
+      index   = i;
+      }
+    }
+  
+  return X[index];
+  }
+
+
+
+template<typename T>
+inline 
+std::complex<T>
+op_min::direct_min(const std::complex<T>* const X, const uword n_elem, uword& index_of_min_val)
+  {
+  arma_extra_debug_sigprint();
+  
+  uword index   = 0;
+  T   min_val = priv::most_pos<T>();
+  
+  for(uword i=0; i<n_elem; ++i)
+    {
+    const T tmp_val = std::abs(X[i]);
+    
+    if(tmp_val < min_val)
+      {
+      min_val = tmp_val;
+      index   = i;
+      }
+    }
+  
+  index_of_min_val = index;
+  
+  return X[index];
+  }
+
+
+
+template<typename T>
+inline 
+std::complex<T>
+op_min::direct_min(const Mat< std::complex<T> >& X, const uword row)
+  {
+  arma_extra_debug_sigprint();
+  
+  const uword X_n_cols = X.n_cols;
+  
+  uword index   = 0;
+  T   min_val = priv::most_pos<T>();
+  
+  for(uword col=0; col<X_n_cols; ++col)
+    {
+    const T tmp_val = std::abs(X.at(row,col));
+    
+    if(tmp_val < min_val)
+      {
+      min_val = tmp_val;
+      index   = col;
+      }
+    }
+  
+  return X.at(row,index);
+  }
+
+
+
+template<typename T>
+inline 
+std::complex<T>
+op_min::direct_min(const subview< std::complex<T> >& X)
+  {
+  arma_extra_debug_sigprint();
+  
+  const uword X_n_elem = X.n_elem;
+        uword index    = 0;
+        T   min_val  = priv::most_pos<T>();
+  
+  for(uword i=0; i<X_n_elem; ++i)
+    {
+    const T tmp_val = std::abs(X[i]);
+    
+    if(tmp_val < min_val)
+      {
+      min_val = tmp_val;
+      index   = i;
+      }
+    }
+  
+  return X[index];
+  }
+
+
+
+template<typename T>
+inline 
+std::complex<T>
+op_min::direct_min(const diagview< std::complex<T> >& X)
+  {
+  arma_extra_debug_sigprint();
+  
+  const uword X_n_elem = X.n_elem;
+        uword index    = 0;
+        T   min_val  = priv::most_pos<T>();
+  
+  for(uword i=0; i<X_n_elem; ++i)
+    {
+    const T tmp_val = std::abs(X[i]);
+    
+    if(tmp_val < min_val)
+      {
+      min_val = tmp_val;
+      index   = i;
+      }
+    }
+  
+  return X[index];
+  }
+
+
+
+//! @}