code: def write_partial_map(filename, data, nside, coord=None, nest=False,
                        header=None,dtype=None,**kwargs):
      
      # ADW: Do we want to make everything uppercase?
  
      if isinstance(data,dict):
          names = list(data.keys())
      else:
          names = data.dtype.names
  
      if 'PIXEL' not in names:
          msg = "'PIXEL' column not found."
          raise ValueError(msg)
  
      hdr = header_odict(nside=nside,coord=coord,nest=nest)
      fitshdr = fitsio.FITSHDR(list(hdr.values()))
      if header is not None:
          for k,v in header.items():
              fitshdr.add_record({'name':k,'value':v})
  
      logger.info("Writing %s"%filename)
      fitsio.write(filename,data,extname='PIX_DATA',header=fitshdr,clobber=True)
docs: Partial HEALPix maps are used to efficiently store maps of the sky by only
      writing out the pixels that contain data.
  
      Three-dimensional data can be saved by supplying a distance modulus array
      which is stored in a separate extension.
  
      Parameters:
      -----------
      filename : output file name
      data     : dictionary or recarray of data to write (must contain 'PIXEL')
      nside    : healpix nside of data
      coord    : 'G'alactic, 'C'elestial, 'E'cliptic
      ordering : 'RING' or 'NEST'
      kwargs   : Passed to fitsio.write
  
      Returns:
      --------
      None