#NEWLINE# @ classmethod #NEWLINE# def _fn( cls , y ) : #NEWLINE# #INDENT# y1 = ( y - 0.1 ) #NEWLINE# xp = ( ( y1 * 27.13 ) / ( 400.0 - y1 ) ) #NEWLINE# x = ( ( ( xp ** ( 1.0 / 0.42 ) ) * 100.0 ) / cls . _FL ) #NEWLINE# return x