例えば、統計学的検定で白黒つけることもできる29> t.test(d[1:15],d[16:30])Welch TwoSample t-test data: d[1:15] and d[16:30]t = -2.6278, df = 27.8, p-value = 0.01383alternative hypothesis: true difference in means isnot equal to 0 95 percent confidence interval: -0.17645650 -0.02183668 sample estimates: mean of xmean of y 0.4788178 0.5779644