window_function.h ソースファイル

 //
 // Copyright (c) 2003-2011, MIST Project, Nagoya University
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without modification,
 // are permitted provided that the following conditions are met:
 //
 // 1. Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
 // 2. Redistributions in binary form must reproduce the above copyright notice,
 // this list of conditions and the following disclaimer in the documentation
 // and/or other materials provided with the distribution.
 //
 // 3. Neither the name of the Nagoya University nor the names of its contributors
 // may be used to endorse or promote products derived from this software
 // without specific prior written permission.
 //
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 #ifndef __INCLUDE_MIST_WINDOW_FUNCTION_H__
 #define __INCLUDE_MIST_WINDOW_FUNCTION_H__
 
 
 #ifndef __INCLUDE_MIST_H__
 #include "../mist.h"
 #endif
 
 #include <cmath>
 
 _MIST_BEGIN
 
 
 namespace window_function
 {
     template < typename T, class Allocator >
     inline void hamming( const array1< T, Allocator > &in, array1< T, Allocator > &out )
     {
         out.resize( in.size( ) );
 
         size_t length = in.size( );
 
         for( size_t i = 0 ; i < length ; i++ )
         {
             double x = static_cast< double >( i ) / static_cast< double >( length );
             out[ i ] = in[ i ] * ( 0.54 - 0.46 * cos( 2.0 * 3.141592 * x ) );
         }
     }
 
 
     template < typename T, class Allocator >
     inline void blackman( const array1< T, Allocator > &in, array1< T, Allocator > &out )
     {
         out.resize( in.size( ) );
 
         size_t length = in.size( );
 
         for( size_t i = 0 ; i < length ; i++ )
         {
             double x = static_cast< double >( i ) / static_cast< double >( length );
             out[ i ] = in[ i ] * ( 0.42 - 0.5 * cos( 2.0 * 3.141592 * x ) + 0.08 * cos( 4.0 * 3.141592 * x ) );
         }
     }
 
 
     template < typename T, class Allocator >
     inline void hann( const array1< T, Allocator > &in, array1< T, Allocator > &out )
     {
         out.resize( in.size( ) );
 
         size_t length = in.size( );
 
         for( size_t i = 0 ; i < length ; i++ )
         {
             double x = static_cast< double >( i ) / static_cast< double >( length );
             out[ i ] = in[ i ] * ( 0.5 - 0.5 * cos( 2.0 * 3.141592 * x ) );
         }
     }
 
 } // namespace window_function
 
 
 _MIST_END
 
 
 #endif
 