public void OnlineMeanSummarizerTest() throws Exception {
Random rnd = new Random();
OnlineMeanSummarizer oms = new OnlineMeanSummarizer();
for (int i = 0; i < 10000; i++)
oms.update(rnd.nextGaussian() * 5 + 1); // should generate mean 1,
// variance 25 or so
Assert.assertTrue(Math.abs(oms.getMean() - 1) < 0.1);
Assert.assertTrue(Math.sqrt(oms.getVariance()) - 25 < 5);
}