question: private void computeSplitValues ( ) { float latMid = ( bb . getLatMin ( ) + bb . getLatMax ( ) ) / 2f ; double width = ( bb . getLonMax ( ) - bb . getLonMin ( ) ) * Math . cos ( latMid * Math . PI / 180.0 ) ; double height = bb . getLatMax ( ) - bb . getLatMin ( ) ; if ( height > width ) { splitAtLat = true ; splitValue = latMid ; } else { splitAtLat = false ; splitValue = ( bb . getLonMin ( ) + bb . getLonMax ( ) ) / 2 ; } }
target:  Splits the bounding box, so that the new boxes have equal size and look square-like as much as possible.