p.adjust不误解BY。本文参考定理1.3(第1182页第5节的证明):
Benjamini,Y.和Yekutieli,D.(2001)。依赖项下多重测试中错误发现率的控制。统计年鉴29,1165年至1188年。
由于本文讨论了几种不同的调整,因此p.adjust()的帮助页面(在撰写本文时)的参考有些模糊。在最一般的依赖结构下,可以保证该方法以指定的速率控制FDR。克里斯托弗·热诺维斯(Christopher Genovese)的幻灯片中提供了丰富的评论,网址为:www.stat.cmu.edu/~genovese/talks/hannover1-04.pdf注意幻灯片37中的评论,指的是BY 2001论文中定理1.3的方法。用p.adjust()的'BY'表示:“很遗憾,这通常非常保守,有时甚至比Bonferroni还要保守。”
数值示例: method='BY'
vsmethod='BH'
以下是Benjamini和Hochberg(2000)论文中使用R的p.adjust()函数将method ='BY'与method ='BH'进行比较的结果,用于表2第2列的p值:
> p <- c(0.85628,0.60282,0.44008,0.41998,0.3864,0.3689,0.31162,0.23522,0.20964,
0.19388,0.15872,0.14374,0.10026,0.08226,0.07912,0.0659,0.05802,0.05572,
0.0549,0.04678,0.0465,0.04104,0.02036,0.00964,0.00904,0.00748,0.00404,
0.00282,0.002,0.0018,2e-05,2e-05,2e-05,0)
> pmat <- rbind(p,p.adjust(p, method='BH'),p.adjust(p, method='BY'))
> rownames(pmat)<-c("pval","adj='BH","adj='BY'")
> round(pmat,4)
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9]
pval 0.8563 0.6028 0.4401 0.4200 0.3864 0.3689 0.3116 0.2352 0.2096
adj='BH 0.8563 0.6211 0.4676 0.4606 0.4379 0.4325 0.3784 0.2962 0.2741
adj='BY' 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000
[,10] [,11] [,12] [,13] [,14] [,15] [,16] [,17] [,18]
pval 0.1939 0.1587 0.1437 0.1003 0.0823 0.0791 0.0659 0.0580 0.0557
adj='BH 0.2637 0.2249 0.2125 0.1549 0.1332 0.1332 0.1179 0.1096 0.1096
adj='BY' 1.0000 0.9260 0.8751 0.6381 0.5485 0.5485 0.4856 0.4513 0.4513
[,19] [,20] [,21] [,22] [,23] [,24] [,25] [,26] [,27]
pval 0.0549 0.0468 0.0465 0.0410 0.0204 0.0096 0.0090 0.0075 0.0040
adj='BH 0.1096 0.1060 0.1060 0.1060 0.0577 0.0298 0.0298 0.0283 0.0172
adj='BY' 0.4513 0.4367 0.4367 0.4367 0.2376 0.1227 0.1227 0.1164 0.0707
[,28] [,29] [,30] [,31] [,32] [,33] [,34]
pval 0.0028 0.0020 0.0018 0e+00 0e+00 0e+00 0
adj='BH 0.0137 0.0113 0.0113 2e-04 2e-04 2e-04 0
adj='BY' 0.0564 0.0467 0.0467 7e-04 7e-04 7e-04 0
∑米我= 1(1 /我)米
> mult <- sapply(c(11, 30, 34, 226, 1674, 12365), function(i)sum(1/(1:i)))
setNames(mult,paste(c('m =',rep('',5)),c(11,30,34,226,1674,12365)))
m = 11 30 34 226 1674 12365
3.020 3.995 4.118 6.000 8.000 10.000
米