code: def _add_axislabels(xlabel,ylabel):
      
      if xlabel != None:
          if xlabel[0] != '$':
              thisxlabel=r'$'+xlabel+'$'
          else:
              thisxlabel=xlabel
          pyplot.xlabel(thisxlabel)
      if ylabel != None:
          if ylabel[0] != '$':
              thisylabel=r'$'+ylabel+'$'
          else:
              thisylabel=ylabel
          pyplot.ylabel(thisylabel)
docs: NAME:
  
         _add_axislabels
  
      PURPOSE:
  
         add axis labels to the current figure
  
      INPUT:
  
         xlabel - (raw string!) x-axis label, LaTeX math mode, no $s needed
  
         ylabel - (raw string!) y-axis label, LaTeX math mode, no $s needed
  
      OUTPUT:
  
         (none; works on the current axes)
  
      HISTORY:
  
         2009-12-23 - Written - Bovy (NYU)