// 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_var
//! @{



//! Class for finding variance values of a matrix
class op_var
  : public traits_op_xvec
  {
  public:
  
  template<typename T1>
  inline static void apply(Mat<typename T1::pod_type>& out, const mtOp<typename T1::pod_type, T1, op_var>& in);
  
  
  //
  
  template<typename eT>
  inline static typename get_pod_type<eT>::result var_vec(const subview_col<eT>& X, const uword norm_type = 0);

  template<typename eT>
  inline static typename get_pod_type<eT>::result var_vec(const subview_row<eT>& X, const uword norm_type = 0);
  
  template<typename T1>
  inline static typename T1::pod_type var_vec(const Base<typename T1::elem_type, T1>& X, const uword norm_type = 0);
  
  
  //
  
  template<typename eT>
  inline static eT direct_var(const eT* const X, const uword N, const uword norm_type = 0);
  
  template<typename eT>
  inline static eT direct_var_robust(const eT* const X, const uword N, const uword norm_type = 0);
  
  
  //
  
  template<typename T>
  inline static  T direct_var(const std::complex<T>* const X, const uword N, const uword norm_type = 0);
  
  template<typename T>
  inline static  T direct_var_robust(const std::complex<T>* const X, const uword N, const uword norm_type = 0);
  };



//! @}