C++ SpMat::zeros方法代码示例

inline
void
op_sp_plus::apply_inside_schur(SpMat<eT>& out, const T2& x, const SpToDOp<T3, op_sp_plus>& y)
  {
  arma_extra_debug_sigprint();

  const SpProxy<T2> proxy2(x);
  const SpProxy<T3> proxy3(y.m);

  arma_debug_assert_same_size(proxy2.get_n_rows(), proxy2.get_n_cols(), proxy3.get_n_rows(), proxy3.get_n_cols(), "element-wise multiplication");

  out.zeros(proxy2.get_n_rows(), proxy2.get_n_cols());
  
  typename SpProxy<T2>::const_iterator_type it     = proxy2.begin();
  typename SpProxy<T2>::const_iterator_type it_end = proxy2.end();
  
  const eT k = y.aux;
  
  for(; it != it_end; ++it)
    {
    const uword it_row = it.row();
    const uword it_col = it.col();
    
    out.at(it_row, it_col) = (*it) * (proxy3.at(it_row, it_col) + k);
    }
  }

arma_hot
inline
void
spop_strans::apply_proxy(SpMat<typename T1::elem_type>& out, const T1& X)
  {
  arma_extra_debug_sigprint();
  
  typedef typename   T1::elem_type  eT;
  typedef typename umat::elem_type ueT;
  
  const SpProxy<T1> p(X);
  
  const uword N = p.get_n_nonzero();
  
  if(N == uword(0))
    {
    out.zeros(p.get_n_cols(), p.get_n_rows());
    return;
    }
  
  umat locs(2, N);
  
  Col<eT> vals(N);
  
  eT* vals_ptr = vals.memptr();
  
  typename SpProxy<T1>::const_iterator_type it = p.begin();
  
  for(uword count = 0; count < N; ++count)
    {
    ueT* locs_ptr = locs.colptr(count);
    
    locs_ptr[0] = it.col();
    locs_ptr[1] = it.row();
    
    vals_ptr[count] = (*it);
    
    ++it;
    }
  
  SpMat<eT> tmp(locs, vals, p.get_n_cols(), p.get_n_rows());
  
  out.steal_mem(tmp);
  }

inline
void
spop_scalar_times::apply(SpMat<typename T1::elem_type>& out, const SpOp<T1,spop_scalar_times>& in)
  {
  arma_extra_debug_sigprint();
  
  typedef typename T1::elem_type eT;
  
  if(in.aux != eT(0))
    {
    out.init_xform(in.m, priv::functor_scalar_times<eT>(in.aux));
    }
  else
    {
    const SpProxy<T1> P(in.m);
    
    out.zeros( P.get_n_rows(), P.get_n_cols() );
    }
  }

arma_hot
inline
void
spop_sum::apply(SpMat<typename T1::elem_type>& out, const SpOp<T1,spop_sum>& in)
  {
  arma_extra_debug_sigprint();
  
  typedef typename T1::elem_type eT;
  
  const uword dim = in.aux_uword_a;
  arma_debug_check( (dim > 1), "sum(): parameter 'dim' must be 0 or 1" );
  
  const SpProxy<T1> p(in.m);
  
  const uword p_n_rows = p.get_n_rows();
  const uword p_n_cols = p.get_n_cols();
  
  if(p.get_n_nonzero() == 0)
    {
    if(dim == 0)  { out.zeros(1,p_n_cols); }
    if(dim == 1)  { out.zeros(p_n_rows,1); }
    
    return;
    }
  
  if(dim == 0) // find the sum in each column
    {
    Row<eT> acc(p_n_cols, fill::zeros);
    
    if(SpProxy<T1>::must_use_iterator)
      {
      typename SpProxy<T1>::const_iterator_type it     = p.begin();
      typename SpProxy<T1>::const_iterator_type it_end = p.end();
      
      while(it != it_end)  { acc[it.col()] += (*it);  ++it; }
      }
    else
      {
      for(uword col = 0; col < p_n_cols; ++col)
        {
        acc[col] = arrayops::accumulate
          (
          &p.get_values()[p.get_col_ptrs()[col]],
          p.get_col_ptrs()[col + 1] - p.get_col_ptrs()[col]
          );
        }
      }
    
    out = acc;
    }
  else
  if(dim == 1)  // find the sum in each row
    {
    Col<eT> acc(p_n_rows, fill::zeros);
    
    typename SpProxy<T1>::const_iterator_type it     = p.begin();
    typename SpProxy<T1>::const_iterator_type it_end = p.end();
    
    while(it != it_end)  { acc[it.row()] += (*it);  ++it; }
    
    out = acc;
    }
  }

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, fill::zeros);
    
    if(SpProxy<T1>::must_use_iterator)
      {
      typename SpProxy<T1>::const_iterator_type it     = p.begin();
      typename SpProxy<T1>::const_iterator_type it_end = p.end();
      
      while(it != it_end)  { acc[it.col()] += (*it);  ++it; }
      
      acc /= T(p_n_rows);
      }
    else
      {
      for(uword col = 0; col < p_n_cols; ++col)
        {
        acc[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, fill::zeros);
    
    typename SpProxy<T1>::const_iterator_type it     = p.begin();
    typename SpProxy<T1>::const_iterator_type it_end = p.end();
    
    while(it != it_end)  { acc[it.row()] += (*it);  ++it; }
    
    acc /= T(p_n_cols);
    
    out = acc;
    }
  
  if(out.is_finite() == false)
    {
    spop_mean::apply_noalias_slow(out, p, dim);
    }
  }

inline
void
spop_diagmat::apply_noalias(SpMat<typename T1::elem_type>& out, const SpProxy<T1>& p)
  {
  arma_extra_debug_sigprint();
  
  const uword n_rows = p.get_n_rows();
  const uword n_cols = p.get_n_cols();
  
  const bool p_is_vec = (n_rows == 1) || (n_cols == 1);
  
  if(p_is_vec)    // generate a diagonal matrix out of a vector
    {
    const uword N = (n_rows == 1) ? n_cols : n_rows;
    
    out.zeros(N, N);
    
    if(p.get_n_nonzero() == 0)  { return; }
    
    typename SpProxy<T1>::const_iterator_type it     = p.begin();
    typename SpProxy<T1>::const_iterator_type it_end = p.end();
      
    if(n_cols == 1)
      {
      while(it != it_end)
        {
        const uword row = it.row();
        
        out.at(row,row) = (*it);
        
        ++it;
        }
      }
    else
    if(n_rows == 1)
      {
      while(it != it_end)
        {
        const uword col = it.col();
        
        out.at(col,col) = (*it);
        
        ++it;
        }
      }
    }
  else   // generate a diagonal matrix out of a matrix
    {
    arma_debug_check( (n_rows != n_cols), "diagmat(): given matrix is not square" );
    
    out.zeros(n_rows, n_rows);
    
    if(p.get_n_nonzero() == 0)  { return; }
    
    typename SpProxy<T1>::const_iterator_type it     = p.begin();
    typename SpProxy<T1>::const_iterator_type it_end = p.end();
      
    while(it != it_end)
      {
      const uword row = it.row();
      const uword col = it.col();
      
      if(row == col)
        {
        out.at(row,row) = (*it);
        }
      
      ++it;
      }
    }
  }

arma_hot
inline
void
spglue_plus::apply_noalias(SpMat<eT>& out, const SpProxy<T1>& pa, const SpProxy<T2>& pb)
  {
  arma_extra_debug_sigprint();
  
  arma_debug_assert_same_size(pa.get_n_rows(), pa.get_n_cols(), pb.get_n_rows(), pb.get_n_cols(), "addition");
  
  if( (pa.get_n_nonzero() != 0) && (pb.get_n_nonzero() != 0) )
    {
    out.zeros(pa.get_n_rows(), pa.get_n_cols());
    
    // Resize memory to correct size.
    out.mem_resize(n_unique(pa, pb, op_n_unique_add()));
    
    // Now iterate across both matrices.
    typename SpProxy<T1>::const_iterator_type x_it = pa.begin();
    typename SpProxy<T2>::const_iterator_type y_it = pb.begin();
    
    typename SpProxy<T1>::const_iterator_type x_end = pa.end();
    typename SpProxy<T2>::const_iterator_type y_end = pb.end();
    
    uword cur_val = 0;
    while( (x_it != x_end) || (y_it != y_end) )
      {
      if(x_it == y_it)
        {
        const eT val = (*x_it) + (*y_it);
        
        if(val != eT(0))
          {
          access::rw(out.values[cur_val]) = val;
          access::rw(out.row_indices[cur_val]) = x_it.row();
          ++access::rw(out.col_ptrs[x_it.col() + 1]);
          ++cur_val;
          }
        
        ++x_it;
        ++y_it;
        }
      else
        {
        const uword x_it_row = x_it.row();
        const uword x_it_col = x_it.col();
        
        const uword y_it_row = y_it.row();
        const uword y_it_col = y_it.col();
        
        if((x_it_col < y_it_col) || ((x_it_col == y_it_col) && (x_it_row < y_it_row))) // if y is closer to the end
          {
          const eT val = (*x_it);
          
          if(val != eT(0))
            {
            access::rw(out.values[cur_val]) = val;
            access::rw(out.row_indices[cur_val]) = x_it_row;
            ++access::rw(out.col_ptrs[x_it_col + 1]);
            ++cur_val;
            }
          
          ++x_it;
          }
        else
          {
          const eT val = (*y_it);
          
          if(val != eT(0))
            {
            access::rw(out.values[cur_val]) = val;
            access::rw(out.row_indices[cur_val]) = y_it_row;
            ++access::rw(out.col_ptrs[y_it_col + 1]);
            ++cur_val;
            }
          
          ++y_it;
          }
        }
      }
    
    const uword out_n_cols = out.n_cols;
    
    uword* col_ptrs = access::rwp(out.col_ptrs);
    
    // Fix column pointers to be cumulative.
    for(uword c = 1; c <= out_n_cols; ++c)
      {
      col_ptrs[c] += col_ptrs[c - 1];
      }
    }
  else
    {
    if(pa.get_n_nonzero() == 0)
      {
      out = pb.Q;
      return;
      }
    
    if(pb.get_n_nonzero() == 0)
      {
//.........这里部分代码省略.........

arma_hot
inline
void
spglue_times::apply_noalias(SpMat<eT>& c, const SpProxy<T1>& pa, const SpProxy<T2>& pb)
  {
  arma_extra_debug_sigprint();
  
  const uword x_n_rows = pa.get_n_rows();
  const uword x_n_cols = pa.get_n_cols();
  const uword y_n_rows = pb.get_n_rows();
  const uword y_n_cols = pb.get_n_cols();

  arma_debug_assert_mul_size(x_n_rows, x_n_cols, y_n_rows, y_n_cols, "matrix multiplication");

  // First we must determine the structure of the new matrix (column pointers).
  // This follows the algorithm described in 'Sparse Matrix Multiplication
  // Package (SMMP)' (R.E. Bank and C.C. Douglas, 2001).  Their description of
  // "SYMBMM" does not include anything about memory allocation.  In addition it
  // does not consider that there may be elements which space may be allocated
  // for but which evaluate to zero anyway.  So we have to modify the algorithm
  // to work that way.  For the "SYMBMM" implementation we will not determine
  // the row indices but instead just the column pointers.
  
  //SpMat<typename T1::elem_type> c(x_n_rows, y_n_cols); // Initializes col_ptrs to 0.
  c.zeros(x_n_rows, y_n_cols);
  
  //if( (pa.get_n_elem() == 0) || (pb.get_n_elem() == 0) )
  if( (pa.get_n_nonzero() == 0) || (pb.get_n_nonzero() == 0) )
    {
    return;
    }
  
  // Auxiliary storage which denotes when items have been found.
  podarray<uword> index(x_n_rows);
  index.fill(x_n_rows); // Fill with invalid links.
  
  typename SpProxy<T2>::const_iterator_type y_it  = pb.begin();
  typename SpProxy<T2>::const_iterator_type y_end = pb.end();

  // SYMBMM: calculate column pointers for resultant matrix to obtain a good
  // upper bound on the number of nonzero elements.
  uword cur_col_length = 0;
  uword last_ind = x_n_rows + 1;
  do
    {
    const uword y_it_row = y_it.row();
    
    // Look through the column that this point (*y_it) could affect.
    typename SpProxy<T1>::const_iterator_type x_it = pa.begin_col(y_it_row);
    
    while(x_it.col() == y_it_row)
      {
      // A point at x(i, j) and y(j, k) implies a point at c(i, k).
      if(index[x_it.row()] == x_n_rows)
        {
        index[x_it.row()] = last_ind;
        last_ind = x_it.row();
        ++cur_col_length;
        }

      ++x_it;
      }

    const uword old_col = y_it.col();
    ++y_it;

    // See if column incremented.
    if(old_col != y_it.col())
      {
      // Set column pointer (this is not a cumulative count; that is done later).
      access::rw(c.col_ptrs[old_col + 1]) = cur_col_length;
      cur_col_length = 0;

      // Return index markers to zero.  Use last_ind for traversal.
      while(last_ind != x_n_rows + 1)
        {
        const uword tmp = index[last_ind];
        index[last_ind] = x_n_rows;
        last_ind = tmp;
        }
      }
    }
  while(y_it != y_end);

  // Accumulate column pointers.
  for(uword i = 0; i < c.n_cols; ++i)
    {
    access::rw(c.col_ptrs[i + 1]) += c.col_ptrs[i];
    }

  // Now that we know a decent bound on the number of nonzero elements, allocate
  // the memory and fill it.
  c.mem_resize(c.col_ptrs[c.n_cols]);

  // Now the implementation of the NUMBMM algorithm.
  uword cur_pos = 0; // Current position in c matrix.
  podarray<eT> sums(x_n_rows); // Partial sums.
  sums.zeros();
  
  // setting the size of 'sorted_indices' to x_n_rows is a better-than-nothing guess;
//.........这里部分代码省略.........