def _romberg_diff(b, c, k):
 tmp = (4.0 ** k)
 return (((tmp * c) - b) / (tmp - 1.0))

def _romberg_diff ( b , c , k ) : tmp = ( 4.0 ** k ) return ( ( ( tmp * c ) - b ) / ( tmp - 1.0 ) )
compute the differences for the romberg quadrature corrections .