/*=========================================================================
 *
 *  Copyright Insight Software Consortium
 *
 *  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.txt
 *
 *  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.
 *
 *=========================================================================*/
#ifndef __itkVariableSizeMatrix_hxx
#define __itkVariableSizeMatrix_hxx

#include "itkVariableSizeMatrix.h"
#include "itkNumericTraits.h"

namespace itk
{
template< typename T >
VariableSizeMatrix< T >
::VariableSizeMatrix(unsigned int rows, unsigned int cols):
  m_Matrix(rows, cols) {}

/**
 *  Product by a Vector
 */
template< typename T >
Array< T >
VariableSizeMatrix< T >
::operator*(const Array< T > & vect) const
{
  unsigned int rows = this->Rows();
  unsigned int cols = this->Cols();

  if ( vect.Size() != cols )
    {
    itkGenericExceptionMacro( << "Matrix with " << this->Cols() << " columns cannot be "
                              << "multiplied with array of length: " << vect.Size() );
    }

  Array< T > result(rows);
  for ( unsigned int r = 0; r < rows; r++ )
    {
    T sum = NumericTraits< T >::Zero;
    for ( unsigned int c = 0; c < cols; c++ )
      {
      sum += m_Matrix(r, c) * vect[c];
      }
    result[r] = sum;
    }
  return result;
}

/**
 *  Product by a matrix
 */
template< typename T >
VariableSizeMatrix< T >
VariableSizeMatrix< T >
::operator*(const Self & matrix) const
{
  if ( this->Cols() != matrix.Rows() )
    {
    itkGenericExceptionMacro(<< "Matrix with size ("
                             << this->Rows() << ","
                             << this->Cols()
                             << ") cannot be multiplied by matrix with size ("
                             << matrix.Rows() << "," << matrix.Cols() << ")");
    }
  Self result;
  result = m_Matrix * matrix.m_Matrix;
  return result;
}

/**
 *  Matrix Addition
 */
template< typename T >
VariableSizeMatrix< T >
VariableSizeMatrix< T >
::operator+(const Self & matrix) const
{
  if ( ( matrix.Rows() != this->Rows() )
       || ( matrix.Cols() != this->Cols() ) )
    {
    itkGenericExceptionMacro(<< "Matrix with size (" << matrix.Rows() << ","
                             << matrix.Cols() << ") cannot be added to a matrix with size ("
                             << this->Rows() << "," << this->Cols() << ")");
    }

  Self result( this->Rows(), this->Cols() );
  for ( unsigned int r = 0; r < this->Rows(); r++ )
    {
    for ( unsigned int c = 0; c < this->Cols(); c++ )
      {
      result.m_Matrix(r, c) = m_Matrix(r, c) + matrix.m_Matrix(r, c);
      }
    }
  return result;
}

/**
 *  Matrix Addition in-place
 */
template< typename T >
const VariableSizeMatrix< T > &
VariableSizeMatrix< T >
::operator+=(const Self & matrix)
{
  if ( ( matrix.Rows() != this->Rows() )
       || ( matrix.Cols() != this->Cols() ) )
    {
    itkGenericExceptionMacro(<< "Matrix with size (" << matrix.Rows() << ","
                             << matrix.Cols() << ") cannot be added to a matrix with size ("
                             << this->Rows() << "," << this->Cols() << ")");
    }

  for ( unsigned int r = 0; r < this->Rows(); r++ )
    {
    for ( unsigned int c = 0; c < this->Cols(); c++ )
      {
      m_Matrix(r, c) += matrix.m_Matrix(r, c);
      }
    }
  return *this;
}

/**
 *  Matrix Subtraction
 */
template< typename T >
VariableSizeMatrix< T >
VariableSizeMatrix< T >
::operator-(const Self & matrix) const
{
  if ( ( matrix.Rows() != this->Rows() )
       || ( matrix.Cols() != this->Cols() ) )
    {
    itkGenericExceptionMacro(<< "Matrix with size (" << matrix.Rows() << ","
                             << matrix.Cols() << ") cannot be subtracted from matrix with size ("
                             << this->Rows() << "," << this->Cols() << ")");
    }

  Self result( this->Rows(), this->Cols() );
  for ( unsigned int r = 0; r < this->Rows(); r++ )
    {
    for ( unsigned int c = 0; c < this->Cols(); c++ )
      {
      result.m_Matrix(r, c) = m_Matrix(r, c) - matrix.m_Matrix(r, c);
      }
    }
  return result;
}

/**
 *  Matrix subtraction in-place
 */
template< typename T >
const VariableSizeMatrix< T > &
VariableSizeMatrix< T >
::operator-=(const Self & matrix)
{
  if ( ( matrix.Rows() != this->Rows() )
       || ( matrix.Cols() != this->Cols() ) )
    {
    itkGenericExceptionMacro(<< "Matrix with size (" << matrix.Rows() << ","
                             << matrix.Cols() << ") cannot be subtracted from matrix with size ("
                             << this->Rows() << "," << this->Cols() << ")");
    }

  for ( unsigned int r = 0; r < this->Rows(); r++ )
    {
    for ( unsigned int c = 0; c < this->Cols(); c++ )
      {
      m_Matrix(r, c) -= matrix.m_Matrix(r, c);
      }
    }
  return *this;
}

template< typename T >
VariableSizeMatrix< T > &
VariableSizeMatrix< T >
::operator-()
{
  for ( unsigned int r = 0; r < this->Rows(); r++ )
    {
    for ( unsigned int c = 0; c < this->Cols(); c++ )
      {
      m_Matrix(r, c) = -m_Matrix(r, c);
      }
    }
  return *this;
}

/**
 *  Product by a vnl_matrix
 */
template< typename T >
vnl_matrix< T >
VariableSizeMatrix< T >
::operator*(const vnl_matrix< T > & matrix) const
{
  return m_Matrix * matrix;
}

/**
 *  Product by a matrix
 */
template< typename T >
void
VariableSizeMatrix< T >
::operator*=(const Self & matrix)
{
  m_Matrix *= matrix.m_Matrix;
}

/**
 *  Product by a vnl_matrix
 */
template< typename T >
void
VariableSizeMatrix< T >
::operator*=(const vnl_matrix< T > & matrix)
{
  m_Matrix *= matrix;
}

/**
 *  Product by a vnl_vector
 */
template< typename T >
vnl_vector< T >
VariableSizeMatrix< T >
::operator*(const vnl_vector< T > & vc) const
{
  return m_Matrix * vc;
}
} // end namespace itk

#endif
