Exemplo n.º 1
0
 def setNoise(self,vexp=None):
     
     """
     Calculate the noise of the dataset, by taking the standard deviation
     of the velocity range lower than v_lsr - 2*vexp. 
     
     If this is not available, the velocity range is taken to be where it is
     smaller than 1.1*vexp.
     
     If the size of the above selection still is too small, None is 
     returned.
     
     The gas terminal velocity has to have been set previously or passed to
     this method as a keyword.
     
     @keyword vexp: The terminal gas velocity, only required if vexp is not 
                    set yet for this LPDataReader object!
                    
                    (default: None)
     @type vexp: float
     
     @return: The noise of the dataset
     @rtype: float
     
     """
     
     if not vexp is None and not self['contents'].has_key('vexp'):
         self['contents']['vexp'] = float(vexp)
     if not self['contents'].has_key('vexp'):
         print 'Cannot set noise without an estimate for the terminal gas'+\
               ' velocity. Pass as keyword to this method!'
         return None
     vel = self['contents']['velocity']
     flux = self['contents']['flux']
     vlsr = self['contents']['vlsr']
     vexp = self['contents']['vexp']
     noise = Data.getStd(wave=vel,flux=flux,wmin=vlsr-5*vexp,\
                         wmax=vlsr-2*vexp,minsize=10)
     if noise is None:
         noise = Data.getStd(wave=vel,flux=flux,wmin=vlsr-3*vexp,\
                             wmax=vlsr-1.8*vexp,minsize=10)
     if noise is None:
         noise = Data.getStd(wave=vel,flux=flux,wmin=vlsr-3*vexp,\
                             wmax=vlsr-1.1*vexp,minsize=10)
     if noise is None:
         noise = Data.getStd(wave=vel,flux=flux,wmin=vlsr-3*vexp,\
                             wmax=vlsr-1.1*vexp,minsize=5)
     if noise is None:
         print 'WARNING! Noise cannot be determined, not enough data ' + \
               'points outside the emission line.'
     self['contents']['noise'] = noise
     
Exemplo n.º 2
0
 def doDataStats(self,method='clipping'):
     
     '''
     Calculate mean, std, rms for the data files.
     
     They are saved in self.data_stats.
     
     @keyword method: Std/Mean/RMS determination method. Can be 'clipping'
                      or 'preset'. The former 1-sigma clips based on 
                      mean/std/... of full spectrum, then takes mean/std/...
                      of clipped spectrum. Latter takes preset values from
                      Data.dat.
                      
                      (default: 'clipping')
     @type method: string
     
     '''
     
     method = method.lower()
     if method not in ['preset','clipping']: method = 'clipping'
     self.data_stats = dict()
     if self.instrument:
         if not self.data_info: self.setDataInfo()
         for filename,data_wave,data_flux,band in \
                     zip(self.instrument.data_filenames,\
                         self.instrument.data_wave_list,\
                         self.instrument.data_flux_list,\
                         self.instrument.data_ordernames):
             these_stats = dict()
             iband = self.data_info['bands'].index(band)
             these_stats['sigma'] = self.data_info['sigmas'][iband]
             if method == 'preset':
                 w_std_min = self.data_info['w_std_min'][iband]
                 w_std_max = self.data_info['w_std_max'][iband]
                 if w_std_min < data_wave[0] or w_std_max > data_wave[-1]:
                     method = 'clipping'
                 test_mean = Data.getMean(wave=data_wave,flux=data_flux,\
                                          wmin=w_std_min,wmax=w_std_max)
                 if test_mean is None:
                     method = 'clipping'
             if method == 'clipping':
                 totmean = Data.getMean(wave=data_wave,flux=data_flux)
                 totstd = Data.getStd(wave=data_wave,flux=data_flux)
                 limits = (-totstd,totstd)
                 these_stats['mean'] = Data.getMean(flux=data_flux,\
                                                    limits=limits)
                 these_stats['std'] = Data.getStd(flux=data_flux,\
                                                  limits=limits)
                 these_stats['rms'] = Data.getRMS(flux=data_flux-\
                                                       these_stats['mean'],\
                                                  limits=limits)                    
             else:
                 these_stats['mean'] = Data.getMean(wave=data_wave,\
                                                    flux=data_flux,\
                                                    wmin=w_std_min,\
                                                    wmax=w_std_max) 
                 these_stats['std'] = Data.getStd(wave=data_wave,\
                                                  flux=data_flux,\
                                                  wmin=w_std_min,\
                                                  wmax=w_std_max)
                 these_stats['rms'] = Data.getRMS(wave=data_wave,\
                                                  flux=data_flux-\
                                                       these_stats['mean'],\
                                                  wmin=w_std_min,\
                                                  wmax=w_std_max)
             print '* Data statistics for %s using "%s" method:'\
                   %(filename,method)
             if method == 'preset':
                 print '* Taken between %.2f and %.2f micron.'\
                       %(w_std_min,w_std_max)
             print 'mean = ',these_stats['mean'],' Jy'
             print 'std = ',these_stats['std'],' Jy'      
             print 'RMS = ',these_stats['rms'],' Jy'      
             self.data_stats[filename] = these_stats
         print '***********************************'