function effective_radius, N0s, mlambda

; N0s has units of #/L/micron and mlambda=1/micron and dge is returned in microns

	if N0s gt 0 then begin

;			N0s=10.^((float(N0s_in[k,jj]))/1000.) & mlambda=10.^((float(mlambda_in[k,jj]))/1000.)


	effective_radius=0.5*0.33*(exp_integral_soln(3., -mlambda, 0., 5000.))/(exp_integral_soln(2., -mlambda, 0., 5000.))
	; the 0.5 is for the conversion from length to radius and the 0.33 is the 1/3 left in the volume to area ratio


	endif


return, effective_radius
end