This file is indexed.

/usr/include/itpp/signal/window.h is in libitpp-dev 4.3.1-2.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
/*!
 * \file
 * \brief Definitions of window functions
 * \author Tony Ottosson, Tobias Ringstrom, Pal Frenger, Adam Piatyszek
 *         and Kumar Appaiah
 *
 * -------------------------------------------------------------------------
 *
 * Copyright (C) 1995-2010  (see AUTHORS file for a list of contributors)
 *
 * This file is part of IT++ - a C++ library of mathematical, signal
 * processing, speech processing, and communications classes and functions.
 *
 * IT++ 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 3 of the License, or (at your option) any
 * later version.
 *
 * IT++ 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 IT++.  If not, see <http://www.gnu.org/licenses/>.
 *
 * -------------------------------------------------------------------------
 */

#ifndef WINDOW_H
#define WINDOW_H

#include <itpp/base/vec.h>
#include <itpp/itexports.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]
*/
ITPP_EXPORT 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.
*/
ITPP_EXPORT 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]
*/
ITPP_EXPORT 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]
*/
ITPP_EXPORT 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]
*/
ITPP_EXPORT vec triang(int n);

/*! \brief Square root window

The square-root of the Triangle window.
sqrt_win(n) = sqrt(triang(n))
*/
ITPP_EXPORT vec sqrt_win(int n);


/*!
  \brief Dolph-Chebyshev window

  The length \c n Dolph-Chebyshev window is a vector \f$w\f$ whose \f$i\f$th
  transform component is given by
  \f[
  W[k] = \frac{T_M\left(\beta \cos\left(\frac{\pi k}{M}\right)
  \right)}{T_M(\beta)},k = 0, 1, 2, \ldots, M - 1
  \f]
  where \c T_n(x) is the order \c n Chebyshev polynomial of the first kind.

  \param n length of the Doplh-Chebyshev window
  \param at attenutation of side lobe (in dB)
  \return symmetric length \c n Doplh-Chebyshev window

  \author Kumar Appaiah and Adam Piatyszek (code review)
*/
ITPP_EXPORT vec chebwin(int n, double at);
//!@}


} //namespace itpp

#endif // #ifndef WINDOW_H