; Given type (string, e.g, "O"), subtype (float, e.g. 3)
; and class (integer), return Mv from
; AQ 4th ed
;

function aq_mv, type, subtype, class
  functionname = 'aq_mv'
  CASE class OF
    5: begin ; Main sequence
	    CASE type OF
		'O': begin 
			x = [5,9] & y = [-5.7, -4.5]
		     end
		'B': begin 
			x = [0,2,5,8] & y = [-4.0, -2.45, -1.2, -0.25]
		     end
		'A': begin 
			x = [0,2,5] & y = [0.65, 1.3, 1.95]
		     end
		'F': begin 
			x = [0,2,5,8] & y = [2.7, 3.6, 3.5, 4.0]
		     end
		'G': begin 
			x = [0,2,5,8] & y = [4.4, 4.7, 5.1, 5.5]
		     end
		'K': begin 
			x = [0,2,5] & y = [5.9, 6.4, 7.35]
		     end
		'M': begin 
			x = [0,2,5] & y = [8.8, 9.9, 12.3]
		     end
	  ENDCASE
       end
    3: begin ; giants. Teff for O-F are from xx
	    CASE type OF
		'G': begin 
			x = [5,8] & y = [0.9, 0.8]
		     end
		'K': begin 
			x = [0,2,5] & y = [0.7, 0.5, -0.2]
		     end
		'M': begin 
			x = [0,2,5] & y = [-0.4, -0.6, -0.3]
		     end
		 ELSE: begin ; out of bounds! 
		    print, functionname+': spectral type out of bounds'
		    return, -100
		    end
	  ENDCASE
       end
    1: begin ; super giants. 
	    CASE type OF
		'B': begin 
 			   x = [2,5,8] 
			   y = [-6.4, -6.2, -6.2]
		     end
		'A': begin 
			x = [0,2,5] & y = [-6.3, -6.5, -6.6]
		     end
		'F': begin 
			x = [0,2,5,8] & y = [-6.6, -6.6, -6.6, -6.5]
		     end
		'G': begin 
			x = [0,2,5,8] & y = [-6.4, -6.3, -6.2, -6.1]
		     end
		'K': begin 
			x = [0,2,5] & y = [-6.0, -5.9, -5.8]
		     end
		'M': begin 
			x = [0,2,5] & y = [-5.6, -5.6, -5.6]
		     end
		  ELSE: begin ; out of bounds! 
		    print, functionname+': spectral type out of bounds'
		    return, -100
		    end
	  ENDCASE
       end
  ELSE: begin ; out of bounds! 
    print, functionname+': spectral type out of bounds'
    return, -100
    end
  ENDCASE

  res = poly_fit(x, y, 1) 
  mv = poly(subtype,res)
  return, mv
end