; Given type (string, eg.g, "O"), subtype (float, e.g. 3)
; and class (integer), return Teff and g from
; AQ 4th ed
;
; Modified Jan 22, 2004 (LAY) to avoid calling poly_fit
; on two-element arrays

pro aq_teff, type, subtype, class, teff, logg, teff_err, logg_err

  gsun = 4.4377 ; from the defined g in the Kurucz frid for T=5770
  CASE class OF
    5: begin ; Main sequence
	    CASE type OF
		'O': begin 
			xt = [5,9] & yt = [42000.,34000.]
			xg = [3,5,6,8] & yg = [-0.3,-0.4,-0.45,-0.5]+gsun
		     end
		'B': begin 
			xt = [0,2,5,8] & yt = [30000,20900,25200,11400]
			xg = [0,3,5,8] & yg = [-0.5,-0.5,-0.4,-0.4]+gsun
		     end
		'A': begin 
			xt = [0,2,5] & yt = [9790,9000,8180]
			xg = [0,5] & yg = [-0.3,-0.15]+gsun
		     end
		'F': begin 
			xt = [0,2,5] & yt = [7300,7000,6650]
			xg = [0,5] & yg = [-0.1,-0.1]+gsun
		     end
		'G': begin 
			xt = [0,2,5,8] & yt = [5940,5790,5560,5310]
			xg = [0,5] & yg = [-0.05,+0.05]+gsun
		     end
		'K': begin 
			xt = [0,2,5] & yt = [5150,4830,4410]
			xg = [0,5] & yg = [+0.05,+0.1]+gsun
		     end
		'M': begin 
			xt = [0,2,5] & yt = [3840,3520,3170]
			xg = [0,2,5,8] & yg = [+0.15,+0.2,+0.5,+0.5]+gsun
		     end
	  ENDCASE
       end
    3: begin ; giants. Teff for O-F are from Humphreys & McElroy 1984
	    CASE type OF
		'O': begin 
			xt = [3,4,5,5.5,6,7,7.5,8,8.5,9,9.5] 
			   yt = [47000,43500,42000,40200,39300,37400,35400,34500, $
			         33600,32800,31900]
			xg = [10,15] & yg = [-1.1,-0.95]+gsun
		     end
		'B': begin 
		     if subtype le 2 then begin
  			   xt = [0,0.2,0.5,0.7,1,1.5,2] 
			   yt = [30300,27300,25900,23400,21100,20000,18000]
			endif else begin
  			   xt = [3,4,5,7,8,9,9.5] 
			   yt = [17100,16700,16300,13200,12550,11400,10550]
			end
			xg = [0,5] & yg = [-1.1,-0.95]+gsun
		     end
		'A': begin 
		     if subtype le 4 then begin
  			   xt = [0,1,2,3,4] 
			   yt = [10000,9570,9000,8500,8200]
			endif else begin
  			   xt = [4,8] 
			   yt = [8200,7800]
			end
			xg = [-5,18] & yg = [-0.95,-1.5]+gsun
		     end
		'F': begin 
			xt = [0,5] & yt = [7000,6500]
			xg = [-15,8] & yg = [-0.95,-1.5]+gsun
		     end
		'G': begin 
			xt = [5,8] & yt = [5050,4800]
			xg = [0,5] & yg = [-1.5,-1.9]+gsun
		     end
		'K': begin 
			xt = [0,2,5] & yt = [4660,4390,4050]
			xg = [0,5] & yg = [-2.3,-2.7]+gsun
		     end
		'M': begin 
			xt = [0,2,5] & yt = [3690,3540,3380]
			xg = [0,2] & yg = [-3.1,-3.3]+gsun
		     end
	  ENDCASE
       end
    1: begin ; super giants. Teff for O-B2 are from Humphreys & McElroy 184
	    CASE type OF
		'O': begin 
			xt = [3,4,5,5.5,6,7,7.5,8,8.5,9,9.5] 
                yt = [48700,45000,43500,41800,40500,37500,$
                  37000,36250,35000,34000,32750]
			xg = [5,6,8] & yg = [-1.1,-1.2,-1.2]+gsun
		     end
		'B': begin 
		     if subtype le 2 then begin
  			   xt = [0,.2,0.5,1,1.5,2] 
			   yt = [29600,28100,25400,24150,21800,19700]
			endif else begin
  			   xt = [2,5,8] 
			   yt = [17600,13600,11100]
			end
			xg = [0,5] & yg = [-1.6,-2.0]+gsun
		     end
		'A': begin 
			xt = [0,2,5] & yt = [9980,9380,8610]
			xg = [0,5] & yg = [-2.3,-2.4]+gsun
		     end
		'F': begin 
			xt = [0,2,5,8] & yt = [7460,7030,6370,5750]
			xg = [0,5] & yg = [-2.7,-3.0]+gsun
		     end
		'G': begin 
			xt = [0,2,5,8] & yt = [5370,5190,4930,4700]
			xg = [0,5] & yg = [-3.1,-3.3]+gsun
		     end
		'K': begin 
			xt = [0,2,5] & yt = [4550,4310,3990]
			xg = [0,5] & yg = [-3.5,-4.1]+gsun
		     end
		'M': begin 
			xt = [0,2,5] & yt = [3620,3370,2880]
			xg = [0,2] & yg = [-4.3,-4.5]+gsun
		     end
	  ENDCASE
       end
  ELSE: begin ; out of bounds! 
    print, 'aq_teff: spectral type out of bounds'
    return
    end
ENDCASE


  if n_elements(xt) gt 2 then begin
    res = linfit(xt, yt) 
    teff = poly(subtype,res)
  end else begin
    teff = yt[0] + (subtype-xt[0])*(yt[1]-yt[0])/(xt[1]-xt[0])
  end 
  teff_err = 250
  if n_elements(xg) gt 2 then begin
    res = linfit(xg, yg) 
    logg = poly(subtype,res)
  end else begin
    logg = yg[0] + (subtype-xg[0])*(yg[1]-yg[0])/(xg[1]-xg[0])
  end 
  logg_err = 0.1  
end