Move into version control

1 files changed, 767 insertions, 0 deletions

diff --git a/src/armadillo/include/armadillo_bits/op_diagmat_meat.hpp b/src/armadillo/include/armadillo_bits/op_diagmat_meat.hpp
new file mode 100644
index 0000000..727da7b
--- /dev/null
+++ b/src/armadillo/include/armadillo_bits/op_diagmat_meat.hpp
@@ -0,0 +1,767 @@
+// 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 op_diagmat
+//! @{
+
+
+
+template<typename T1>
+inline
+void
+op_diagmat::apply(Mat<typename T1::elem_type>& out, const Op<T1, op_diagmat>& X)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename T1::elem_type eT;
+  
+  if(is_Mat<T1>::value)
+    {
+    // allow detection of in-place operation
+    
+    const unwrap<T1>   U(X.m);
+    const Mat<eT>& A = U.M;
+    
+    if(&out != &A)  // no aliasing
+      {
+      const Proxy< Mat<eT> > P(A);
+      
+      op_diagmat::apply(out, P);
+      }
+    else  // we have aliasing
+      {
+      const uword n_rows = out.n_rows;
+      const uword n_cols = out.n_cols;
+      
+      if((n_rows == 1) || (n_cols == 1))  // create diagonal matrix from vector
+        {
+        const eT*   out_mem = out.memptr();
+        const uword N       = out.n_elem;
+        
+        Mat<eT> tmp(N,N, arma_zeros_indicator());
+        
+        for(uword i=0; i<N; ++i)  { tmp.at(i,i) = out_mem[i]; }
+        
+        out.steal_mem(tmp);
+        }
+      else  // create diagonal matrix from matrix
+        {
+        const uword N = (std::min)(n_rows, n_cols);
+        
+        for(uword i=0; i < n_cols; ++i)
+          {
+          if(i < N)
+            {
+            eT& out_ii = out.at(i,i);
+            
+            const eT val = out_ii;
+            
+            arrayops::fill_zeros(out.colptr(i), n_rows);
+            
+            out_ii = val;
+            }
+          else
+            {
+            arrayops::fill_zeros(out.colptr(i), n_rows);
+            }
+          }
+        }
+      }
+    }
+  else
+    {
+    const Proxy<T1> P(X.m);
+    
+    if(P.is_alias(out))
+      {
+      Mat<eT> tmp;
+      
+      op_diagmat::apply(tmp, P);
+      
+      out.steal_mem(tmp);
+      }
+    else
+      {
+      op_diagmat::apply(out, P);
+      }
+    }
+  }
+
+
+
+template<typename T1>
+inline
+void
+op_diagmat::apply(Mat<typename T1::elem_type>& out, const Proxy<T1>& P)
+  {
+  arma_extra_debug_sigprint();
+  
+  const uword n_rows = P.get_n_rows();
+  const uword n_cols = P.get_n_cols();
+  const uword n_elem = P.get_n_elem();
+  
+  if(n_elem == 0)  { out.reset(); return; }
+  
+  const bool P_is_vec = (T1::is_row) || (T1::is_col) || (n_rows == 1) || (n_cols == 1);
+  
+  if(P_is_vec)
+    {
+    out.zeros(n_elem, n_elem);
+    
+    if(Proxy<T1>::use_at == false)
+      {
+      typename Proxy<T1>::ea_type Pea = P.get_ea();
+      
+      for(uword i=0; i < n_elem; ++i)  { out.at(i,i) = Pea[i]; }
+      }
+    else
+      {
+      if(n_rows == 1)
+        {
+        for(uword i=0; i < n_elem; ++i)  { out.at(i,i) = P.at(0,i); }
+        }
+      else
+        {
+        for(uword i=0; i < n_elem; ++i)  { out.at(i,i) = P.at(i,0); }
+        }
+      }
+    }
+  else  // P represents a matrix 
+    {
+    out.zeros(n_rows, n_cols);
+    
+    const uword N = (std::min)(n_rows, n_cols);
+    
+    for(uword i=0; i<N; ++i)  { out.at(i,i) = P.at(i,i); }
+    }
+  }
+
+
+
+template<typename T1, typename T2>
+inline
+void
+op_diagmat::apply(Mat<typename T1::elem_type>& out, const Op< Glue<T1,T2,glue_times>, op_diagmat>& X)
+  {
+  arma_extra_debug_sigprint();
+  
+  op_diagmat::apply_times(out, X.m.A, X.m.B);
+  }
+
+
+
+template<typename T1, typename T2>
+inline
+void
+op_diagmat::apply_times(Mat<typename T1::elem_type>& actual_out, const T1& X, const T2& Y, const typename arma_not_cx<typename T1::elem_type>::result* junk)
+  {
+  arma_extra_debug_sigprint();
+  arma_ignore(junk);
+  
+  typedef typename T1::elem_type eT;
+  
+  const partial_unwrap<T1> UA(X);
+  const partial_unwrap<T2> UB(Y);
+  
+  const typename partial_unwrap<T1>::stored_type& A = UA.M;
+  const typename partial_unwrap<T2>::stored_type& B = UB.M;
+  
+  arma_debug_assert_trans_mul_size< partial_unwrap<T1>::do_trans, partial_unwrap<T2>::do_trans >(A.n_rows, A.n_cols, B.n_rows, B.n_cols, "matrix multiplication");
+  
+  const bool use_alpha = partial_unwrap<T1>::do_times || partial_unwrap<T2>::do_times;
+  const eT       alpha = use_alpha ? (UA.get_val() * UB.get_val()) : eT(0);
+  
+  const uword A_n_rows = A.n_rows;
+  const uword A_n_cols = A.n_cols;
+
+  const uword B_n_rows = B.n_rows;
+  const uword B_n_cols = B.n_cols;
+  
+  // check if the multiplication results in a vector
+  
+  if( (partial_unwrap<T1>::do_trans == false) && (partial_unwrap<T2>::do_trans == false) )
+    {
+    if((A_n_rows == 1) || (B_n_cols == 1))
+      {
+      arma_extra_debug_print("trans_A = false; trans_B = false; vector result");
+      
+      const Mat<eT> C     = A*B;
+      const eT*     C_mem = C.memptr();
+      const uword   N     = C.n_elem;
+      
+      actual_out.zeros(N,N);
+      
+      for(uword i=0; i<N; ++i)  { actual_out.at(i,i) = (use_alpha) ? eT(alpha * C_mem[i]) : eT(C_mem[i]); }
+      
+      return;
+      }
+    }
+  else
+  if( (partial_unwrap<T1>::do_trans == true ) && (partial_unwrap<T2>::do_trans == false) )
+    {
+    if((A_n_cols == 1) || (B_n_cols == 1))
+      {
+      arma_extra_debug_print("trans_A = true; trans_B = false; vector result");
+      
+      const Mat<eT> C     = trans(A)*B;
+      const eT*     C_mem = C.memptr();
+      const uword   N     = C.n_elem;
+      
+      actual_out.zeros(N,N);
+      
+      for(uword i=0; i<N; ++i)  { actual_out.at(i,i) = (use_alpha) ? eT(alpha * C_mem[i]) : eT(C_mem[i]); }
+      
+      return;
+      }
+    }
+  else
+  if( (partial_unwrap<T1>::do_trans == false) && (partial_unwrap<T2>::do_trans == true ) )
+    {
+    if((A_n_rows == 1) || (B_n_rows == 1))
+      {
+      arma_extra_debug_print("trans_A = false; trans_B = true; vector result");
+      
+      const Mat<eT> C     = A*trans(B);
+      const eT*     C_mem = C.memptr();
+      const uword   N     = C.n_elem;
+      
+      actual_out.zeros(N,N);
+      
+      for(uword i=0; i<N; ++i)  { actual_out.at(i,i) = (use_alpha) ? eT(alpha * C_mem[i]) : eT(C_mem[i]); }
+      
+      return;
+      }
+    }
+  else
+  if( (partial_unwrap<T1>::do_trans == true ) && (partial_unwrap<T2>::do_trans == true ) )
+    {
+    if((A_n_cols == 1) || (B_n_rows == 1))
+      {
+      arma_extra_debug_print("trans_A = true; trans_B = true; vector result");
+      
+      const Mat<eT> C     = trans(A)*trans(B);
+      const eT*     C_mem = C.memptr();
+      const uword   N     = C.n_elem;
+      
+      actual_out.zeros(N,N);
+      
+      for(uword i=0; i<N; ++i)  { actual_out.at(i,i) = (use_alpha) ? eT(alpha * C_mem[i]) : eT(C_mem[i]); }
+      
+      return;
+      }
+    }
+  
+  // if we got to this point, the multiplication results in a matrix
+
+  const bool is_alias = (UA.is_alias(actual_out) || UB.is_alias(actual_out));
+  
+  Mat<eT>  tmp;
+  Mat<eT>& out = (is_alias) ? tmp : actual_out;
+  
+  if( (partial_unwrap<T1>::do_trans == false) && (partial_unwrap<T2>::do_trans == false) )
+    {
+    arma_extra_debug_print("trans_A = false; trans_B = false; matrix result");
+    
+    out.zeros(A_n_rows, B_n_cols);
+    
+    const uword N = (std::min)(A_n_rows, B_n_cols);
+    
+    for(uword k=0; k < N; ++k)
+      {
+      eT acc1 = eT(0);
+      eT acc2 = eT(0);
+      
+      const eT* B_colptr = B.colptr(k);
+      
+      // condition: A_n_cols = B_n_rows
+      
+      uword j;
+      
+      for(j=1; j < A_n_cols; j+=2)
+        {
+        const uword i = (j-1);
+        
+        const eT tmp_i = B_colptr[i];
+        const eT tmp_j = B_colptr[j];
+        
+        acc1 += A.at(k, i) * tmp_i;
+        acc2 += A.at(k, j) * tmp_j;
+        }
+      
+      const uword i = (j-1);
+      
+      if(i < A_n_cols)
+        {
+        acc1 += A.at(k, i) * B_colptr[i];
+        }
+      
+      const eT acc = acc1 + acc2;
+      
+      out.at(k,k) = (use_alpha) ? eT(alpha * acc) : eT(acc);
+      }
+    }
+  else
+  if( (partial_unwrap<T1>::do_trans == true ) && (partial_unwrap<T2>::do_trans == false) )
+    {
+    arma_extra_debug_print("trans_A = true; trans_B = false; matrix result");
+    
+    out.zeros(A_n_cols, B_n_cols);
+    
+    const uword N = (std::min)(A_n_cols, B_n_cols);
+    
+    for(uword k=0; k < N; ++k)
+      {
+      const eT* A_colptr = A.colptr(k);
+      const eT* B_colptr = B.colptr(k);
+      
+      // condition: A_n_rows = B_n_rows
+      
+      const eT acc = op_dot::direct_dot(A_n_rows, A_colptr, B_colptr);
+      
+      out.at(k,k) = (use_alpha) ? eT(alpha * acc) : eT(acc);
+      }
+    }
+  else
+  if( (partial_unwrap<T1>::do_trans == false) && (partial_unwrap<T2>::do_trans == true ) )
+    {
+    arma_extra_debug_print("trans_A = false; trans_B = true; matrix result");
+    
+    out.zeros(A_n_rows, B_n_rows);
+    
+    const uword N = (std::min)(A_n_rows, B_n_rows);
+    
+    for(uword k=0; k < N; ++k)
+      {
+      eT acc = eT(0);
+      
+      // condition: A_n_cols = B_n_cols
+      
+      for(uword i=0; i < A_n_cols; ++i)
+        {
+        acc += A.at(k,i) * B.at(k,i);
+        }
+      
+      out.at(k,k) = (use_alpha) ? eT(alpha * acc) : eT(acc);
+      }
+    }
+  else
+  if( (partial_unwrap<T1>::do_trans == true ) && (partial_unwrap<T2>::do_trans == true ) )
+    {
+    arma_extra_debug_print("trans_A = true; trans_B = true; matrix result");
+    
+    out.zeros(A_n_cols, B_n_rows);
+    
+    const uword N = (std::min)(A_n_cols, B_n_rows);
+    
+    for(uword k=0; k < N; ++k)
+      {
+      eT acc = eT(0);
+      
+      const eT* A_colptr = A.colptr(k);
+      
+      // condition: A_n_rows = B_n_cols
+      
+      for(uword i=0; i < A_n_rows; ++i)
+        {
+        acc += A_colptr[i] * B.at(k,i);
+        }
+      
+      out.at(k,k) = (use_alpha) ? eT(alpha * acc) : eT(acc);
+      }
+    }
+  
+  if(is_alias)  { actual_out.steal_mem(tmp); }
+  }
+
+
+
+template<typename T1, typename T2>
+inline
+void
+op_diagmat::apply_times(Mat<typename T1::elem_type>& actual_out, const T1& X, const T2& Y, const typename arma_cx_only<typename T1::elem_type>::result* junk)
+  {
+  arma_extra_debug_sigprint();
+  arma_ignore(junk);
+  
+  typedef typename T1::pod_type   T;
+  typedef typename T1::elem_type eT;
+  
+  const partial_unwrap<T1> UA(X);
+  const partial_unwrap<T2> UB(Y);
+  
+  const typename partial_unwrap<T1>::stored_type& A = UA.M;
+  const typename partial_unwrap<T2>::stored_type& B = UB.M;
+  
+  arma_debug_assert_trans_mul_size< partial_unwrap<T1>::do_trans, partial_unwrap<T2>::do_trans >(A.n_rows, A.n_cols, B.n_rows, B.n_cols, "matrix multiplication");
+  
+  const bool use_alpha = partial_unwrap<T1>::do_times || partial_unwrap<T2>::do_times;
+  const eT       alpha = use_alpha ? (UA.get_val() * UB.get_val()) : eT(0);
+  
+  const uword A_n_rows = A.n_rows;
+  const uword A_n_cols = A.n_cols;
+  
+  const uword B_n_rows = B.n_rows;
+  const uword B_n_cols = B.n_cols;
+  
+  // check if the multiplication results in a vector
+  
+  if( (partial_unwrap<T1>::do_trans == false) && (partial_unwrap<T2>::do_trans == false) )
+    {
+    if((A_n_rows == 1) || (B_n_cols == 1))
+      {
+      arma_extra_debug_print("trans_A = false; trans_B = false; vector result");
+      
+      const Mat<eT> C     = A*B;
+      const eT*     C_mem = C.memptr();
+      const uword   N     = C.n_elem;
+      
+      actual_out.zeros(N,N);
+      
+      for(uword i=0; i<N; ++i)  { actual_out.at(i,i) = (use_alpha) ? eT(alpha * C_mem[i]) : eT(C_mem[i]); }
+      
+      return;
+      }
+    }
+  else
+  if( (partial_unwrap<T1>::do_trans == true ) && (partial_unwrap<T2>::do_trans == false) )
+    {
+    if((A_n_cols == 1) || (B_n_cols == 1))
+      {
+      arma_extra_debug_print("trans_A = true; trans_B = false; vector result");
+      
+      const Mat<eT> C     = trans(A)*B;
+      const eT*     C_mem = C.memptr();
+      const uword   N     = C.n_elem;
+      
+      actual_out.zeros(N,N);
+      
+      for(uword i=0; i<N; ++i)  { actual_out.at(i,i) = (use_alpha) ? eT(alpha * C_mem[i]) : eT(C_mem[i]); }
+      
+      return;
+      }
+    }
+  else
+  if( (partial_unwrap<T1>::do_trans == false) && (partial_unwrap<T2>::do_trans == true ) )
+    {
+    if((A_n_rows == 1) || (B_n_rows == 1))
+      {
+      arma_extra_debug_print("trans_A = false; trans_B = true; vector result");
+      
+      const Mat<eT> C     = A*trans(B);
+      const eT*     C_mem = C.memptr();
+      const uword   N     = C.n_elem;
+      
+      actual_out.zeros(N,N);
+      
+      for(uword i=0; i<N; ++i)  { actual_out.at(i,i) = (use_alpha) ? eT(alpha * C_mem[i]) : eT(C_mem[i]); }
+      
+      return;
+      }
+    }
+  else
+  if( (partial_unwrap<T1>::do_trans == true ) && (partial_unwrap<T2>::do_trans == true ) )
+    {
+    if((A_n_cols == 1) || (B_n_rows == 1))
+      {
+      arma_extra_debug_print("trans_A = true; trans_B = true; vector result");
+      
+      const Mat<eT> C     = trans(A)*trans(B);
+      const eT*     C_mem = C.memptr();
+      const uword   N     = C.n_elem;
+      
+      actual_out.zeros(N,N);
+      
+      for(uword i=0; i<N; ++i)  { actual_out.at(i,i) = (use_alpha) ? eT(alpha * C_mem[i]) : eT(C_mem[i]); }
+      
+      return;
+      }
+    }
+  
+  // if we got to this point, the multiplication results in a matrix
+
+  const bool is_alias = (UA.is_alias(actual_out) || UB.is_alias(actual_out));
+  
+  Mat<eT>  tmp;
+  Mat<eT>& out = (is_alias) ? tmp : actual_out;
+  
+  if( (partial_unwrap<T1>::do_trans == false) && (partial_unwrap<T2>::do_trans == false) )
+    {
+    arma_extra_debug_print("trans_A = false; trans_B = false; matrix result");
+    
+    out.zeros(A_n_rows, B_n_cols);
+    
+    const uword N = (std::min)(A_n_rows, B_n_cols);
+    
+    for(uword k=0; k < N; ++k)
+      {
+      T acc_real = T(0);
+      T acc_imag = T(0);
+      
+      const eT* B_colptr = B.colptr(k);
+      
+      // condition: A_n_cols = B_n_rows
+      
+      for(uword i=0; i < A_n_cols; ++i)
+        {
+        // acc += A.at(k, i) * B_colptr[i];
+        
+        const std::complex<T>& xx = A.at(k, i);
+        const std::complex<T>& yy = B_colptr[i];
+        
+        const T a = xx.real();
+        const T b = xx.imag();
+        
+        const T c = yy.real();
+        const T d = yy.imag();
+        
+        acc_real += (a*c) - (b*d);
+        acc_imag += (a*d) + (b*c);
+        }
+      
+      const eT acc = std::complex<T>(acc_real, acc_imag);
+      
+      out.at(k,k) = (use_alpha) ? eT(alpha * acc) : eT(acc);
+      }
+    }
+  else
+  if( (partial_unwrap<T1>::do_trans == true) && (partial_unwrap<T2>::do_trans == false) )
+    {
+    arma_extra_debug_print("trans_A = true; trans_B = false; matrix result");
+    
+    out.zeros(A_n_cols, B_n_cols);
+    
+    const uword N = (std::min)(A_n_cols, B_n_cols);
+    
+    for(uword k=0; k < N; ++k)
+      {
+      T acc_real = T(0);
+      T acc_imag = T(0);
+      
+      const eT* A_colptr = A.colptr(k);
+      const eT* B_colptr = B.colptr(k);
+      
+      // condition: A_n_rows = B_n_rows
+      
+      for(uword i=0; i < A_n_rows; ++i)
+        {
+        // acc += std::conj(A_colptr[i]) * B_colptr[i];
+        
+        const std::complex<T>& xx = A_colptr[i];
+        const std::complex<T>& yy = B_colptr[i];
+        
+        const T a = xx.real();
+        const T b = xx.imag();
+        
+        const T c = yy.real();
+        const T d = yy.imag();
+        
+        // take into account the complex conjugate of xx
+        
+        acc_real += (a*c) + (b*d);
+        acc_imag += (a*d) - (b*c);
+        }
+      
+      const eT acc = std::complex<T>(acc_real, acc_imag);
+      
+      out.at(k,k) = (use_alpha) ? eT(alpha * acc) : eT(acc);
+      }
+    }
+  else
+  if( (partial_unwrap<T1>::do_trans == false) && (partial_unwrap<T2>::do_trans == true) )
+    {
+    arma_extra_debug_print("trans_A = false; trans_B = true; matrix result");
+    
+    out.zeros(A_n_rows, B_n_rows);
+    
+    const uword N = (std::min)(A_n_rows, B_n_rows);
+    
+    for(uword k=0; k < N; ++k)
+      {
+      T acc_real = T(0);
+      T acc_imag = T(0);
+      
+      // condition: A_n_cols = B_n_cols
+      
+      for(uword i=0; i < A_n_cols; ++i)
+        {
+        // acc += A.at(k,i) * std::conj(B.at(k,i));
+        
+        const std::complex<T>& xx = A.at(k, i);
+        const std::complex<T>& yy = B.at(k, i);
+        
+        const T a = xx.real();
+        const T b = xx.imag();
+        
+        const T c =  yy.real();
+        const T d = -yy.imag();  // take the conjugate
+        
+        acc_real += (a*c) - (b*d);
+        acc_imag += (a*d) + (b*c);
+        }
+      
+      const eT acc = std::complex<T>(acc_real, acc_imag);
+      
+      out.at(k,k) = (use_alpha) ? eT(alpha * acc) : eT(acc);
+      }
+    }
+  else
+  if( (partial_unwrap<T1>::do_trans == true) && (partial_unwrap<T2>::do_trans == true) )
+    {
+    arma_extra_debug_print("trans_A = true; trans_B = true; matrix result");
+    
+    out.zeros(A_n_cols, B_n_rows);
+    
+    const uword N = (std::min)(A_n_cols, B_n_rows);
+    
+    for(uword k=0; k < N; ++k)
+      {
+      T acc_real = T(0);
+      T acc_imag = T(0);
+      
+      const eT* A_colptr = A.colptr(k);
+      
+      // condition: A_n_rows = B_n_cols
+      
+      for(uword i=0; i < A_n_rows; ++i)
+        {
+        // acc += std::conj(A_colptr[i]) * std::conj(B.at(k,i));
+        
+        const std::complex<T>& xx = A_colptr[i];
+        const std::complex<T>& yy = B.at(k, i);
+        
+        const T a =  xx.real();
+        const T b = -xx.imag();  // take the conjugate
+        
+        const T c =  yy.real();
+        const T d = -yy.imag();  // take the conjugate
+        
+        acc_real += (a*c) - (b*d);
+        acc_imag += (a*d) + (b*c);
+        }
+      
+      const eT acc = std::complex<T>(acc_real, acc_imag);
+      
+      out.at(k,k) = (use_alpha) ? eT(alpha * acc) : eT(acc);
+      }
+    }
+  
+  if(is_alias)  { actual_out.steal_mem(tmp); }
+  }
+
+
+
+//
+//
+//
+
+
+
+template<typename T1>
+inline
+void
+op_diagmat2::apply(Mat<typename T1::elem_type>& out, const Op<T1, op_diagmat2>& X)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename T1::elem_type eT;
+  
+  const uword row_offset = X.aux_uword_a;
+  const uword col_offset = X.aux_uword_b;
+  
+  const Proxy<T1> P(X.m);
+  
+  if(P.is_alias(out))
+    {
+    Mat<eT> tmp;
+    
+    op_diagmat2::apply(tmp, P, row_offset, col_offset);
+    
+    out.steal_mem(tmp);
+    }
+  else
+    {
+    op_diagmat2::apply(out, P, row_offset, col_offset);
+    }
+  }
+
+
+
+template<typename T1>
+inline
+void
+op_diagmat2::apply(Mat<typename T1::elem_type>& out, const Proxy<T1>& P, const uword row_offset, const uword col_offset)
+  {
+  arma_extra_debug_sigprint();
+  
+  const uword n_rows = P.get_n_rows();
+  const uword n_cols = P.get_n_cols();
+  const uword n_elem = P.get_n_elem();
+  
+  if(n_elem == 0)  { out.reset(); return; }
+  
+  const bool P_is_vec = (T1::is_row) || (T1::is_col) || (n_rows == 1) || (n_cols == 1);
+  
+  if(P_is_vec)
+    {
+    const uword n_pad = (std::max)(row_offset, col_offset);
+    
+    out.zeros(n_elem + n_pad, n_elem + n_pad);
+    
+    if(Proxy<T1>::use_at == false)
+      {
+      typename Proxy<T1>::ea_type Pea = P.get_ea();
+      
+      for(uword i=0; i < n_elem; ++i)  { out.at(row_offset + i, col_offset + i) = Pea[i]; }
+      }
+    else
+      {
+      if(n_rows == 1)
+        {
+        for(uword i=0; i < n_elem; ++i)  { out.at(row_offset + i, col_offset + i) = P.at(0,i); }
+        }
+      else
+        {
+        for(uword i=0; i < n_elem; ++i)  { out.at(row_offset + i, col_offset + i) = P.at(i,0); }
+        }
+      }
+    }
+  else  // P represents a matrix 
+    {
+    arma_debug_check_bounds
+      (
+      ((row_offset > 0) && (row_offset >= n_rows)) || ((col_offset > 0) && (col_offset >= n_cols)),
+      "diagmat(): requested diagonal out of bounds"
+      );
+    
+    out.zeros(n_rows, n_cols);
+    
+    const uword N = (std::min)(n_rows - row_offset, n_cols - col_offset);
+    
+    for(uword i=0; i<N; ++i)
+      {
+      const uword row = i + row_offset;
+      const uword col = i + col_offset;
+      
+      out.at(row,col) = P.at(row,col);
+      }
+    }
+  }
+
+
+
+//! @}