Source Code for Module pylal.lalfft

 1  # Copyright (C) 2009  Kipp Cannon 
 2  # 
 3  # This program is free software; you can redistribute it and/or modify it 
 4  # under the terms of the GNU General Public License as published by the 
 5  # Free Software Foundation; either version 2 of the License, or (at your 
 6  # option) any later version. 
 7  # 
 8  # This program is distributed in the hope that it will be useful, but 
 9  # WITHOUT ANY WARRANTY; without even the implied warranty of 
10  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General 
11  # Public License for more details. 
12  # 
13  # You should have received a copy of the GNU General Public License along 
14  # with this program; if not, write to the Free Software Foundation, Inc., 
15  # 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA. 
16   
17   
18  # 
19  # ============================================================================= 
20  # 
21  #                                   Preamble 
22  # 
23  # ============================================================================= 
24  # 
25   
26   
27  """ 
28  This module provides some utilities to assist with FFTs 
29  """ 
30   
31   
32  import lal 
33   
34   
35  import git_version 
36   
37   
38  __author__ = "Kipp Cannon <kipp.cannon@ligo.org>" 
39  __version__ = "git id %s" % git_version.id 
40  __date__ = git_version.date 
41   
42   
43  # 
44  # ============================================================================= 
45  # 
46  #                                  Utilities 
47  # 
48  # ============================================================================= 
49  # 
50   
51   
52 -def prepare_fseries_for_real8tseries(series): 
53          """ 
54          Construct a COMPLEX16FrequencySeries object suitable for storing 
55          the Fourier transform of a REAL8TimeSeries object. 
56          """ 
57          n = len(series.data.data) 
58          return lal.CreateCOMPLEX16FrequencySeries( 
59                  name = series.name, 
60                  epoch = series.epoch, 
61                  f0 = series.f0, # note: non-zero f0 not supported by LAL 
62                  deltaF = 1.0 / (n * series.deltaT), 
63                  sampleUnits = series.sampleUnits * lal.SecondUnit, 
64                  length = n // 2 + 1 
65          ) 
66   
67   
68 -def prepare_fseries_for_complex16tseries(series): 
69          """ 
70          Construct a COMPLEX16FrequencySeries object suitable for storing 
71          the Fourier transform of a COMPLEX16TimeSeries object. 
72          """ 
73          n = len(series.data.data) 
74          return lal.CreateCOMPLEX16FrequencySeries( 
75                  name = series.name, 
76                  epoch = series.epoch, 
77                  f0 = series.f0, # note: non-zero f0 not supported by LAL 
78                  deltaF = 1.0 / (n * series.deltaT), 
79                  sampleUnits = series.sampleUnits * lal.SecondUnit, 
80                  length = n 
81          ) 
82