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/*!
* \file
* \brief Definitions of window functions
* \author Tony Ottosson, Tobias Ringstrom, Pal Frenger and Adam Piatyszek
*
* -------------------------------------------------------------------------
*
* IT++ - C++ library of mathematical, signal processing, speech processing,
* and communications classes and functions
*
* Copyright (C) 1995-2008 (see AUTHORS file for a list of contributors)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* -------------------------------------------------------------------------
*/
#ifndef WINDOW_H
#define WINDOW_H
#include <itpp/base/vec.h>
namespace itpp {
/*!
\addtogroup windfunc
*/
/*!\addtogroup windfunc
\brief Windowing functions
*/
//!@{
/*! \brief Hamming window
The \c n size Hamming window is a vector \f$w\f$ where the \f$i\f$th component is
\f[
w_i = 0.54 - 0.46 \cos(2\pi i/(n-1))
\f]
*/
vec hamming(int size);
/*! \brief Hanning window
The \c n size Hanning window is a vector \f$w\f$ where the \f$i\f$th component is
\f[
w_i = 0.5(1 - \cos(2\pi (i+1)/(n+1))
\f]
Observe that this function is not the same as the hann() function which is defined
as in matlab.
*/
vec hanning(int n);
/*! \brief Hanning window compatible with matlab
The \c n size Hanning window is a vector \f$w\f$ where the \f$i\f$th component is
\f[
w_i = 0.5(1 - \cos(2\pi i/(n-1))
\f]
*/
vec hann(int n);
/*! \brief Blackman window
The \c n size Blackman window is a vector \f$w\f$ where the \f$i\f$th component is
\f[
w_i = 0.42 - 0.5\cos(2\pi i/(n-1)) + 0.08\cos(4\pi i/(n-1))
\f]
*/
vec blackman(int n);
/*! \brief Triangular window
The \c n size triangle window is a vector \f$w\f$ where the \f$i\f$th component is
\f[
w_i = w_{n-i-1} = \frac{2(i+1)}{n+1}
\f]
for \c n odd and for \c n even
\f[
w_i = w_{n-i-1} = \frac{2i+1}{n}
\f]
*/
vec triang(int n);
/*! \brief Square root window
The square-root of the Triangle window.
sqrt_win(n) = sqrt(triang(n))
*/
vec sqrt_win(int n);
//!@}
} //namespace itpp
#endif // #ifndef WINDOW_H
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