我试图根据对照组的(dx = 1)均值和标准差创建z-评分变量。我想循环所有我感兴趣的变量(PCT:CST.L)来创建这些z分数。我将如何做到这一点?这是我的数据。在R循环中创建变量
X dx PCT CST.R CST.L
1 1 Control 15 30 5
2 2 Control 20 24 22
3 3 Clinical 25 20 14
4 4 Control 17 13 12
5 5 Clinical 14 12 11
6 6 Control 13 20 15
而且在这里,我希望它看起来像(至少是标题,至少)。
X dx PCT CST.R CST.L PCT_Z CST.R_Z CST.L_Z
1 1 Control 15 30 5
2 2 Control 20 24 22
3 3 Clinical 25 20 14
4 4 Control 17 13 12
5 5 Clinical 14 12 11
6 6 Control 13 20 15
数据
structure(list(X = 1:6, dx = c("Control", "Control", "Clinical",
"Control", "Clinical", "Control"), PCT = c(15L, 20L, 25L, 17L,
14L, 13L), CST.R = c(30L, 24L, 20L, 13L, 12L, 20L), CST.L = c(5L,
22L, 14L, 12L, 11L, 15L)), .Names = c("X", "dx", "PCT", "CST.R",
"CST.L"), class = "data.frame", row.names = c("1", "2", "3",
"4", "5", "6"))
dd [,paste0(c(“PCT”,“CST.R”,“CST.L”),'_Z')] < - scale(dd [,c(“PCT”,“ CST.R“,”CST.L“)])' – rawr
[related](http://stackoverflow.com/questions/6148050/creating-z-scores)我没有读得很好。你想通过控制和临床组获得zscores?我不知道'dx = 1'的意思和sd是什么意思 - 没有一个单一的观测sd – rawr