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

function aq_jh, type, subtype, class
  functionname = 'aq_jh'
  CASE class OF
    5: begin ; Main sequence
	    CASE type OF
		'O': begin 
			x = [9,9.5] & y = [-0.14,-0.13]
		     end
		'B': begin 
			x = [0,1,2,3,4,5,6,7,8,9] 
			y = [-0.12,-0.10,-0.09,-0.08,-0.07,-0.06,-0.05, -0.03,-0.03,-0.01]
		     end
		'A': begin 
			x = [0,2,5,7] & y = [0.00,0.02,0.06,0.09]
		     end
		'F': begin 
			x = [0,2,5,7] & y = [0.13,0.17,0.23,0.29]
		     end
		'G': begin 
			x = [0,2,4,6] & y = [0.31,0.32,0.33,0.37]
		     end
		'K': begin 
			x = [0,2,4,5,7]
			y = [0.45,0.50,0.58,0.61,0.66]
		     end
		'M': begin 
			x = [0,1,2,3,4,5,6] 
			y = [0.67,0.66,0.66,0.64,0.62,0.62,0.66]
		     end
	  ENDCASE
       end
    3: begin ; giants. Teff for O-F are from xx
	    CASE type OF
		'G': begin 
			x = [0,4,6,8] & y = [0.37,0.47,0.50,0.50]
		     end
		'K': begin 
			x = [0,1,2,3,4,5] & y = [0.54,0.58,0.63,0.68,0.73,0.79]
		     end
		'M': begin 
			x = [0,1,2,3,4,5,6,7]
			y = [0.83,0.85,0.87,0.90,0.93,0.95,0.96,0.96]
		     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 = [5,6,7,8,9] 
			   y = [0.01,0.04,0.06,0.07,0.08]
		     end
		'A': begin 
			x = [0,1,2,5] & y = [0.09,0.11,0.12,0.13]
		     end
		'F': begin 
			x = [0,2,5,8] & y = [0.15,0.18,0.22,0.28]
		     end
		'G': begin 
			x = [0,3,8] & y = [0.33,0.38,0.43]
		     end
		'K': begin 
			x = [0,1,2,3,5] & y = [0.46,0.49,0.52,0.59,0.67]
		     end
		'M': begin 
			x = [0,1,2,3,4] & y = [0.73,0.73,0.73,0.74,078]
		     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) 
;  color = poly(subtype,res)
  color = interpol(y,x,subtype)
  return, color
end