docs: def drawMask(self,ax=None, mask=None, mtype='maglim'):
          """ Draw the maglim from the mask. """
          if not ax: ax = plt.gca()
          if mask is None:
              mask = ugali.analysis.loglike.createMask(self.config,roi=self.roi)
  
          mask_map = hp.UNSEEN*np.ones(hp.nside2npix(self.nside))
          if mtype.lower() == 'maglim':
              mask_map[mask.roi.pixels] = mask.mask_1.mask_roi_sparse
          elif mtype.lower() == 'fracdet':
              mask_map[mask.roi.pixels] = mask.mask_1.frac_roi_sparse
          else:
              raise Exception("Unrecognized type: %s"%mtype)
          masked = (mask_map==hp.UNSEEN) | (mask_map==0)
          mask_map = np.ma.array(mask_map,mask=masked,fill_value=np.nan)
  
          im = drawHealpixMap(mask_map,self.lon,self.lat,self.radius,coord=self.coord)
  
          try: cbar = ax.cax.colorbar(im)
          except: cbar = plt.colorbar(im)
          cbar.ax.set_xticklabels(cbar.ax.get_xticklabels(),rotation=90)
          ax.annotate(mtype,**self.label_kwargs)
          return im