docs: def pixelizeCatalog(infiles, config, force=False):
      """
      Break catalog into chunks by healpix pixel.
      
      Parameters:
      -----------
      infiles : List of input files
      config  : Configuration file
      force   : Overwrite existing files (depricated)
      
      Returns:
      --------
      None
      """
      nside_catalog = config['coords']['nside_catalog']
      nside_pixel = config['coords']['nside_pixel']
      coordsys = config['coords']['coordsys'].upper()
      outdir = mkdir(config['catalog']['dirname'])
      filenames = config.getFilenames()
      lon_field = config['catalog']['lon_field'].upper()
      lat_field = config['catalog']['lat_field'].upper()
  
      # ADW: It would probably be better (and more efficient) to do the
      # pixelizing and the new column insertion separately.
      for i,filename in enumerate(infiles):
          logger.info('(%i/%i) %s'%(i+1, len(infiles), filename))
          data = fitsio.read(filename)
          logger.info("%i objects found"%len(data))
          if not len(data): continue
  
          columns = map(str.upper,data.dtype.names)
          names,arrs = [],[]
  
          if (lon_field in columns) and (lat_field in columns):
              lon,lat = data[lon_field],data[lat_field]
          elif coordsys == 'GAL':
              msg = "Columns '%s' and '%s' not found."%(lon_field,lat_field)
              msg += "\nConverting from RA,DEC"
              logger.warning(msg)
              lon,lat = cel2gal(data['RA'],data['DEC'])
              names += [lon_field,lat_field]
              arrs  += [lon,lat]
          elif coordsys == 'CEL':
              msg = "Columns '%s' and '%s' not found."%(lon_field,lat_field)
              msg += "\nConverting from GLON,GLAT"
              lon,lat = gal2cel(data['GLON'],data['GLAT'])
              names  += [lon_field,lat_field]
              arrs   += [lon,lat]
  
          cat_pix = ang2pix(nside_catalog,lon,lat)
          pix_pix = ang2pix(nside_pixel,lon,lat)
          cat_pix_name = 'PIX%i'%nside_catalog
          pix_pix_name = 'PIX%i'%nside_pixel
  
          try:
              names += [cat_pix_name,pix_pix_name]
              arrs  += [cat_pix,pix_pix]
              data=mlab.rec_append_fields(data,names=names,arrs=arrs)
          except ValueError as e:
              logger.warn(str(e)+'; not adding column.')
              #data[cat_pix_name] = cat_pix
              #data[pix_pix_name] = pix_pix
                                 
          for pix in np.unique(cat_pix):
              logger.debug("Processing pixel %s"%pix)
  
              arr = data[cat_pix == pix]
              outfile = filenames.data['catalog'][pix]
  
              if not os.path.exists(outfile):
                  logger.debug("Creating %s"%outfile)
                  out=fitsio.FITS(outfile,mode='rw')
                  out.write(arr)
  
                  hdr=healpix.header_odict(nside=nside_catalog,
                                                       coord=coordsys[0])
                  for key in ['PIXTYPE','ORDERING','NSIDE','COORDSYS']:
                      out[1].write_key(*list(hdr[key].values()))
                  out[1].write_key('PIX',pix,comment='HEALPIX pixel for this file')
              else:
                  out=fitsio.FITS(outfile,mode='rw')
                  out[1].append(arr)
  
              logger.debug("Writing %s"%outfile)
              out.close()