FUNCTION fit_simul_function,p

common func_simul_xy, x, y1, y2, y3, y4

;The function we are trying to fit is
;y=((d+(k0/kl)^(1/(b-4))*D)/po))^(b-2)
;
;p(0)=kox
;p(1)=koy
;p(2)=kl
;p(3)=kt
;p(4)=b
;p(5)=po


a=1./(p(4)-4)
b=p(4)-2
koxl=float(p(0)/p(2))
koyl=float(p(1)/p(2))
koxt=float(p(0)/p(3))
koyt=float(p(1)/p(3))


;xtrans
xtrans_tot=total((y1-p(3)*(((x+(koxt^a)*.17)/p(5))^b*$
	          (5e-7/(x+(koxt^a)*.17))^2))^2)
;xlong
xlong_tot=total((y2-p(2)*(((x+(koxl^a)*.17)/p(5))^b*$
                  (5e-7/(x+(koxl^a)*.17))^2))^2)
;ytrans
ytrans_tot=total((y3-p(3)*(((x+(koyt^a)*.17)/p(5))^b*$
                  (5e-7/(x+(koyt^a)*.17))^2))^2)

;ylong
ylong_tot=total((y4-p(2)*(((x+(koyl^a)*.17)/p(5))^b*$
                  (5e-7/(x+(koyl^a)*.17))^2))^2)

return,((ylong_tot+ytrans_tot+xlong_tot+xtrans_tot))

end