Source Code for Module qubx.data_acquire

 1  """Reads .acquire data files. 
 2   
 3  Copyright 2008-2011 Research Foundation State University of New York  
 4  This file is part of QUB Express.                                           
 5   
 6  QUB Express is free software; you can redistribute it and/or modify           
 7  it under the terms of the GNU General Public License as published by  
 8  the Free Software Foundation, either version 3 of the License, or     
 9  (at your option) any later version.                                   
10   
11  QUB Express is distributed in the hope that it will be useful,                
12  but WITHOUT ANY WARRANTY; without even the implied warranty of        
13  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         
14  GNU General Public License for more details.                          
15   
16  You should have received a copy of the GNU General Public License,    
17  named LICENSE.txt, in the QUB Express program directory.  If not, see         
18  <http://www.gnu.org/licenses/>.                                       
19   
20  """ 
21   
22  from qubx.data_types import * 
23  from qubx.acquirefile import * 
24   
25   
26 -class QubData_ACQ_Analog(QubData_Analog): 
27 -    def __init__(self, data, channel): 
28          """ 
29          @param data: L{QubData_ACQ} 
30  """ 
31          QubData_Analog.__init__(self) 
32          self.data = data 
33          self.channel = channel 
34 -    def read(self, first, last, latency=0, skip=1): 
35          ifirst, ilast = [self.data.segmentation.index_at(x) for x in (first, last)] 
36          if ifirst != ilast: 
37              raise Exception("Acquirefile: can't read() from multiple segments at once") 
38          segfirst = self.data.segmentation.segments[ifirst][0] 
39          seglast = self.data.segmentation.segments[ifirst][1] 
40          return read_with_latency(self.read_in_seg, first, last, latency, skip, ifirst, segfirst, seglast) 
41 -    def read_in_seg(self, iseg, first, last, skip): 
42          series, sweep = self.data.ser_sweep_of_seg[iseg] 
43          samples = self.data.file.read_data_float32(series, sweep, iseg, self.channel, first, last-first+1) 
44          scale = self.data.signals.get(self.channel, 'Scale') 
45          if scale != 1.0: 
46              samples *= scale 
47          offset = self.data.signals.get(self.channel, 'Offset') 
48          if offset != 0.0: 
49              samples += offset 
50          return samples 
51           
52   
53 -class QubData_ACQ(QubData): 
54      """One open Aquire data file. 
55   
56  @ivar file: L{qubx.acquirefile.AcquireFile} 
57  """ 
58 -    def __init__(self, path, progressf): 
59          QubData.__init__(self) 
60          self.path = path 
61          self.file = AcquireFile(path) 
62          self.sampling = self.file.sampling_sec 
63           
64          for c in xrange(self.file.header.analog_in_channel_count): 
65              self.signals.append({'Name' : self.file.ai_channels[c].label, 
66                                   'Units' : self.file.ai_channels[c].units}) 
67              self.set_analog(c, QubData_ACQ_Analog(self, c)) 
68               
69          last = -1 
70          i = 0 
71          self.ser_sweep_of_seg = [] 
72          for r, series in enumerate(self.file.series): 
73              for w, sweep in enumerate(series.sweeps): 
74                  for g, seg in enumerate(sweep.sweep.segments): 
75                      seglen = sum(block.data_count for block in seg.channels[0]) 
76                      first = last + 1 
77                      last = first + seglen - 1 
78                      self.ser_sweep_of_seg.append((r,w)) 
79                      self.segmentation.add_seg(first, last, first*1e3*self.sampling) 
80                       
81          base, ext = os.path.splitext(path) 
82          sess = qubx.tree.Open(base+'.qsf', True) 
83          sess.close() # release file, keep in mem 
84   
85          # override QuB's integer scaling values 
86          for chan in qubx.tree.children(sess.find('DataChannels'), 'Channel'): 
87              chan['Scaling'].data = 1.0 
88              chan['Offset'].data = 0.0 
89   
90          self.read_session(sess, progressf) 
91           
92   
93  SetReader('.acquire', 'Acquire files', QubData_ACQ) 
94