double qtop = sortedList.get(sortedList.getNtile(NTILE - 1, NTILE)).doubleValue();
double r = qtop - qbottom; // range
double lowerbound = qbottom - ALPHA * r;
double upperbound = qtop + ALPHA * r;
// box it
double yd = y.doubleValue();
yd = Math.max(yd, lowerbound);
yd = Math.min(yd, upperbound);
if (yd != y.doubleValue()) {
logger.debug("boxed outlier: range: {}-{}={} orig data: {} filt data: {}",
qbottom, qtop, qtop - qbottom, v.doubleValue(), yd);