private static int stToIJ(double s){
  final int m=MAX_SIZE / 2;
  return (int)Math.max(0,Math.min(2 * m - 1,Math.round(m * s + (m - 0.5))));
}

private static int stToIJ ( double s ) { final int m = MAX_SIZE / 2 ; return ( int ) Math . max ( 0 , Math . min ( 2 * m - 1 , Math . round ( m * s + ( m - 0.5 ) ) ) ) ; }
return the i - or j - index of the leaf cell containing the given s - or t - value .
