filters.cc 3.73 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
/*! \file filter.cc
 * \brief filter types (implementation)
 * 
 * ----------------------------------------------------------------------------
 * 
 * \author Thomas Forbriger
 * \date 05/01/2003
 * 
 * filter types (implementation)
 * 
 * Copyright (c) 2003 by Thomas Forbriger (IMG Frankfurt) 
 *
 * ----
14
 * libfourier is free software; you can redistribute it and/or modify
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
 * 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
 * ----
 *
 * 
 * REVISIONS and CHANGES 
 *  - 05/01/2003   V1.0   Thomas Forbriger
 * 
 * ============================================================================
 */
#define TF_FILTER_CC_VERSION \
36
  "TF_FILTER_CC   V1.0"
37
38
39

#include <fourier/filters.h>
#include <fourier/error.h>
40
#include <cmath>
41
42
43

namespace fourier {

44
  const double Filter::pi=M_PI;
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
  const Filter::Tcvalue Filter::ime=Tcvalue(0.,1.);

  /*----------------------------------------------------------------------*/

  Filter::Tcvalue Filter::omega(const Filter::Tcvalue& par) const 
  {
    Tcvalue retval;
    if (isfreqmod()) { retval=2.*pi*par; } else { retval=2.*pi/par; }
    return(retval);
  }

  /*----------------------------------------------------------------------*/

  void Filter::setint()
  {
     this->Tbase::setpole(Tcvalue(0.,0.));
     this->Tbase::denfactor(Tcvalue(0.,1.));
  }

  /*----------------------------------------------------------------------*/

  void Filter::setdif()
  {
     this->Tbase::setzero(Tcvalue(0.,0.));
     this->Tbase::numfactor(Tcvalue(0.,1.));
  }

  /*----------------------------------------------------------------------*/

  void Filter::sethpb(const Filter::Tcvalue& par, const int& ord) 
  {
    Tcvalue om=omega(par);
    FOURIER_assert((ord>0), "ERROR (Filter hpb): illegal order!");
    for (int i=1; i<=ord; ++i)
    {
      this->Tbase::setzero(Tcvalue(0.,0.));
      Tcvalue pole=om*std::exp(ime*pi*(2.*i-1.)/(2.*ord));
      this->Tbase::setpole(pole);
    }
  }

  /*----------------------------------------------------------------------*/

  void Filter::setlpb(const Filter::Tcvalue& par, const int& ord) 
  {
    Tcvalue om=omega(par);
    FOURIER_assert((ord>0), "ERROR (Filter lpb): illegal order!");
    for (int i=1; i<=ord; ++i)
    {
      this->Tbase::numfactor(-ime*om);
      Tcvalue pole=om*std::exp(ime*pi*(2.*i-1.)/(2.*ord));
      this->Tbase::setpole(pole);
    }
  }

  /*----------------------------------------------------------------------*/

  void Filter::sethp2(const Filter::Tcvalue& par, const double& h) 
  {
    Tcvalue om=omega(par);
    this->Tbase::setzero(Tcvalue(0.,0.));
    this->Tbase::setzero(Tcvalue(0.,0.));
    Tcvalue pole=om*(ime*h+std::sqrt(1.-h*h));
    this->Tbase::setpole(pole);
    pole=om*(ime*h-std::sqrt(1.-h*h));
    this->Tbase::setpole(pole);
  }

  /*----------------------------------------------------------------------*/

  void Filter::setlp2(const Filter::Tcvalue& par, const double& h) 
  {
    Tcvalue om=omega(par);
    this->Tbase::numfactor(-ime*om);
    this->Tbase::numfactor(-ime*om);
    Tcvalue pole=om*(ime*h+std::sqrt(1.-h*h));
    this->Tbase::setpole(pole);
    pole=om*(ime*h-std::sqrt(1.-h*h));
    this->Tbase::setpole(pole);
  }

} // namespace fourier

/* ----- END OF filter.cc ----- */