old_contents: 
  '''
  Split MS into single spectral channels
  '''
  
  import os
  
  from tasks import split
  from taskinit import tb
  
  from .mytools import mymstransform
  
  
  def split_by_channel(vis, nchan=-1, start=1, spw=0,
                       restfreq='1420.40575177MHz'):
      '''
      Splits a MS by its spectral channels, according to the given
      '''
  
      # Get the total number of channels
      tb.open(os.path.join(vis, '/SPECTRAL_WINDOW'))
      nchan_list = tb.getcol('NUM_CHAN')
      tb.close()
  
      # Pick out the spw specified
      total_nchan = nchan_list[spw]
  
      # Now create a list of the channels to use
      if nchan == -1:
          nchan = total_nchan
      elif nchan > total_nchan:
          raise ValueError("There are only "+str(total_nchan)+". Reduce"
                           " nchan to at least this")
      else:
          pass
  
      channel_list = range(start, start+nchan)
  
      for chan in channel_list:
          channel_vis = vis.rstrip(".ms")+"_channel_"+str(chan)+".ms"
          mymstransform(vis=vis, outputvis=channel_vis, spw=spw,
                        regridms=True, width=1, nchan=1, start=chan,
                        restfreq=restfreq)
  
new_contents: 
  '''
  Split MS into single spectral channels
  '''
  
  import os
  
  from taskinit import tb
  
  from .mytools import mymstransform
  
  
  def split_by_channel(vis, nchan=-1, start=1, spw=0,
                       restfreq='1420.40575177MHz'):
      '''
      Splits a MS by its spectral channels, according to the given
      '''
  
      # Get the total number of channels
      tb.open(os.path.join(vis, '/SPECTRAL_WINDOW'))
      nchan_list = tb.getcol('NUM_CHAN')
      tb.close()
  
      # Pick out the spw specified
      total_nchan = nchan_list[spw]
  
      # Now create a list of the channels to use
      if nchan == -1:
          nchan = total_nchan
      elif nchan > total_nchan:
          raise ValueError("There are only "+str(total_nchan)+". Reduce"
                           " nchan to at least this")
      else:
          pass
  
      channel_list = range(start, start+nchan)
  
      for chan in channel_list:
          channel_vis = vis.rstrip(".ms")+"_channel_"+str(chan)+".ms"
          mymstransform(vis=vis, outputvis=channel_vis, spw=spw,
                        regridms=True, width=1, nchan=1, start=chan,
                        restfreq=restfreq)
  
subject: Remove old import