1 files changed, 376 insertions, 0 deletions
diff --git a/src/armadillo/include/armadillo_bits/spop_mean_meat.hpp b/src/armadillo/include/armadillo_bits/spop_mean_meat.hpp
new file mode 100644
index 0000000..dd97916
--- /dev/null
+++ b/src/armadillo/include/armadillo_bits/spop_mean_meat.hpp
@@ -0,0 +1,376 @@
+// SPDX-License-Identifier: Apache-2.0
+// 
+// Copyright 2008-2016 Conrad Sanderson (http://conradsanderson.id.au)
+// Copyright 2008-2016 National ICT Australia (NICTA)
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ------------------------------------------------------------------------
+
+
+//! \addtogroup spop_mean
+//! @{
+
+
+
+template<typename T1>
+inline
+void
+spop_mean::apply(SpMat<typename T1::elem_type>& out, const SpOp<T1, spop_mean>& in)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename T1::elem_type eT;
+  
+  const uword dim = in.aux_uword_a;
+  arma_debug_check( (dim > 1), "mean(): parameter 'dim' must be 0 or 1" );
+  
+  const SpProxy<T1> p(in.m);
+  
+  if(p.is_alias(out) == false)
+    {
+    spop_mean::apply_noalias_fast(out, p, dim);
+    }
+  else
+    {
+    SpMat<eT> tmp;
+    
+    spop_mean::apply_noalias_fast(tmp, p, dim);
+    
+    out.steal_mem(tmp);
+    }
+  }
+
+
+
+template<typename T1>
+inline
+void
+spop_mean::apply_noalias_fast
+  (
+        SpMat<typename T1::elem_type>& out,
+  const SpProxy<T1>&                   p,
+  const uword                          dim
+  )
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename T1::elem_type eT;
+  typedef typename T1::pod_type   T;
+  
+  const uword p_n_rows = p.get_n_rows();
+  const uword p_n_cols = p.get_n_cols();
+  
+  if( (p_n_rows == 0) || (p_n_cols == 0) || (p.get_n_nonzero() == 0) )
+    {
+    if(dim == 0)  { out.zeros((p_n_rows > 0) ? 1 : 0, p_n_cols); }
+    if(dim == 1)  { out.zeros(p_n_rows, (p_n_cols > 0) ? 1 : 0); }
+    
+    return;
+    }
+  
+  if(dim == 0) // find the mean in each column
+    {
+    Row<eT> acc(p_n_cols, arma_zeros_indicator());
+    
+    eT* acc_mem = acc.memptr();
+    
+    if(SpProxy<T1>::use_iterator)
+      {
+      typename SpProxy<T1>::const_iterator_type it = p.begin();
+      
+      const uword N = p.get_n_nonzero();
+      
+      for(uword i=0; i < N; ++i)  { acc_mem[it.col()] += (*it); ++it; }
+      
+      acc /= T(p_n_rows);
+      }
+    else
+      {
+      for(uword col = 0; col < p_n_cols; ++col)
+        {
+        acc_mem[col] = arrayops::accumulate
+          (
+          &p.get_values()[p.get_col_ptrs()[col]],
+          p.get_col_ptrs()[col + 1] - p.get_col_ptrs()[col]
+          ) / T(p_n_rows);
+        }
+      }
+    
+    out = acc;
+    }
+  else
+  if(dim == 1)  // find the mean in each row
+    {
+    Col<eT> acc(p_n_rows, arma_zeros_indicator());
+    
+    eT* acc_mem = acc.memptr();
+    
+    typename SpProxy<T1>::const_iterator_type it = p.begin();
+    
+    const uword N = p.get_n_nonzero();
+    
+    for(uword i=0; i < N; ++i)  { acc_mem[it.row()] += (*it); ++it; }
+    
+    acc /= T(p_n_cols);
+    
+    out = acc;
+    }
+  
+  if(out.internal_has_nonfinite())
+    {
+    spop_mean::apply_noalias_slow(out, p, dim);
+    }
+  }
+
+
+
+template<typename T1>
+inline
+void
+spop_mean::apply_noalias_slow
+  (
+        SpMat<typename T1::elem_type>& out,
+  const SpProxy<T1>&                   p,
+  const uword                          dim
+  )
+  {
+  arma_extra_debug_sigprint();
+
+  typedef typename T1::elem_type eT;
+  
+  const uword p_n_rows = p.get_n_rows();
+  const uword p_n_cols = p.get_n_cols();
+
+  if(dim == 0)  // find the mean in each column
+    {
+    arma_extra_debug_print("spop_mean::apply_noalias(): dim = 0");
+    
+    out.set_size((p_n_rows > 0) ? 1 : 0, p_n_cols);
+    
+    if( (p_n_rows == 0) || (p.get_n_nonzero() == 0) )  { return; }
+    
+    for(uword col = 0; col < p_n_cols; ++col)
+      {
+      // Do we have to use an iterator or can we use memory directly?
+      if(SpProxy<T1>::use_iterator)
+        {
+        typename SpProxy<T1>::const_iterator_type it  = p.begin_col(col);
+        typename SpProxy<T1>::const_iterator_type end = p.begin_col(col + 1);
+        
+        const uword n_zero = p_n_rows - (end.pos() - it.pos());
+        
+        out.at(0,col) = spop_mean::iterator_mean(it, end, n_zero, eT(0));
+        }
+      else
+        {
+        out.at(0,col) = spop_mean::direct_mean
+          (
+          &p.get_values()[p.get_col_ptrs()[col]],
+          p.get_col_ptrs()[col + 1] - p.get_col_ptrs()[col],
+          p_n_rows
+          );
+        }
+      }
+    }
+  else
+  if(dim == 1)  // find the mean in each row
+    {
+    arma_extra_debug_print("spop_mean::apply_noalias(): dim = 1");
+    
+    out.set_size(p_n_rows, (p_n_cols > 0) ? 1 : 0);
+    
+    if( (p_n_cols == 0) || (p.get_n_nonzero() == 0) )  { return; }
+    
+    for(uword row = 0; row < p_n_rows; ++row)
+      {
+      // We must use an iterator regardless of how it is stored.
+      typename SpProxy<T1>::const_row_iterator_type it  = p.begin_row(row);
+      typename SpProxy<T1>::const_row_iterator_type end = p.end_row(row);
+      
+      const uword n_zero = p_n_cols - (end.pos() - it.pos());
+      
+      out.at(row,0) = spop_mean::iterator_mean(it, end, n_zero, eT(0));
+      }
+    }
+  }
+
+
+
+template<typename eT>
+inline
+eT
+spop_mean::direct_mean
+  (
+  const eT* const X,
+  const uword length,
+  const uword N
+  )
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename get_pod_type<eT>::result T;
+  
+  const eT result = ((length > 0) && (N > 0)) ? eT(arrayops::accumulate(X, length) / T(N)) : eT(0);
+  
+  return arma_isfinite(result) ? result : spop_mean::direct_mean_robust(X, length, N);
+  }
+
+
+
+template<typename eT>
+inline
+eT
+spop_mean::direct_mean_robust
+  (
+  const eT* const X,
+  const uword length,
+  const uword N
+  )
+  {
+  arma_extra_debug_sigprint();
+
+  typedef typename get_pod_type<eT>::result T;
+
+  uword i, j;
+
+  eT r_mean = eT(0);
+
+  const uword diff = (N - length); // number of zeros
+
+  for(i = 0, j = 1; j < length; i += 2, j += 2)
+    {
+    const eT Xi = X[i];
+    const eT Xj = X[j];
+
+    r_mean += (Xi - r_mean) / T(diff + j);
+    r_mean += (Xj - r_mean) / T(diff + j + 1);
+    }
+
+  if(i < length)
+    {
+    const eT Xi = X[i];
+
+    r_mean += (Xi - r_mean) / T(diff + i + 1);
+    }
+
+  return r_mean;
+  }
+
+
+
+template<typename T1>
+inline
+typename T1::elem_type
+spop_mean::mean_all(const SpBase<typename T1::elem_type, T1>& X)
+  {
+  arma_extra_debug_sigprint();
+  
+  SpProxy<T1> p(X.get_ref());
+  
+  if(SpProxy<T1>::use_iterator)
+    {
+    typename SpProxy<T1>::const_iterator_type it  = p.begin();
+    typename SpProxy<T1>::const_iterator_type end = p.end();
+
+    return spop_mean::iterator_mean(it, end, p.get_n_elem() - p.get_n_nonzero(), typename T1::elem_type(0));
+    }
+  else // use_iterator == false; that is, we can directly access the values array
+    {
+    return spop_mean::direct_mean(p.get_values(), p.get_n_nonzero(), p.get_n_elem());
+    }
+  }
+
+
+
+template<typename T1, typename spop_type>
+inline
+typename T1::elem_type
+spop_mean::mean_all(const SpOp<T1, spop_type>& expr)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename T1::elem_type eT;
+  
+  const bool is_vectorise = \
+       (is_same_type<spop_type, spop_vectorise_row>::yes)
+    || (is_same_type<spop_type, spop_vectorise_col>::yes)
+    || (is_same_type<spop_type, spop_vectorise_all>::yes);
+  
+  if(is_vectorise)
+    {
+    return spop_mean::mean_all(expr.m);
+    }
+  
+  const SpMat<eT> tmp = expr;
+  
+  return spop_mean::mean_all(tmp);
+  }
+
+
+
+template<typename T1, typename eT>
+inline
+eT
+spop_mean::iterator_mean(T1& it, const T1& end, const uword n_zero, const eT junk)
+  {
+  arma_extra_debug_sigprint();
+  arma_ignore(junk);
+  
+  typedef typename get_pod_type<eT>::result T;
+  
+  eT acc = eT(0);
+  
+  T1 backup_it(it); // in case we have to use robust iterator_mean
+  
+  const uword it_begin_pos = it.pos();
+  
+  while(it != end)
+    {
+    acc += (*it);
+    ++it;
+    }
+  
+  const uword count = n_zero + (it.pos() - it_begin_pos);
+  
+  const eT result = (count > 0) ? eT(acc / T(count)) : eT(0);
+  
+  return arma_isfinite(result) ? result : spop_mean::iterator_mean_robust(backup_it, end, n_zero, eT(0));
+  }
+
+
+
+template<typename T1, typename eT>
+inline
+eT
+spop_mean::iterator_mean_robust(T1& it, const T1& end, const uword n_zero, const eT junk)
+  {
+  arma_extra_debug_sigprint();
+  arma_ignore(junk);
+
+  typedef typename get_pod_type<eT>::result T;
+
+  eT r_mean = eT(0);
+
+  const uword it_begin_pos = it.pos();
+
+  while(it != end)
+    {
+    r_mean += ((*it - r_mean) / T(n_zero + (it.pos() - it_begin_pos) + 1));
+    ++it;
+    }
+
+  return r_mean;
+  }
+
+
+
+//! @}