我的数据如下：
'data.frame': 798 obs. of 16 variables:
$ READMIT.ENCOUNTER : int (intentionally blank)
$ MRN : int (intentionally blank)
$ READMIT.SOURCE : Factor w/ 5 levels "Emergency Unit",..: 5 1 1 1 5 1 1 1 1 1 ...
$ READMIT.DATE : Factor w/ 300 levels "1/1/2013","1/11/2013",..: 83 25 92 88 4 92 26 18 24 9 ...
$ READMIT.DISC.DATE : Factor w/ 284 levels "1/10/2013","1/11/2013",..: 10 8 22 22 14 26 3 25 1 112 ...
$ READMIT.MONTH : int 1 1 1 1 1 1 1 1 1 2 ...
$ READMIT.YEAR : int 2013 2013 2013 2013 2013 2013 2013 2013 2013 2013 ...
$ LOS : int 11 10 4 7 11 8 4 4 3 18 ...
$ INTERIM : int 24 27 27 19 29 4 21 9 18 18 ...
$ READMIT.INSURANCE : Factor w/ 33 levels "A12","A13","B03",..: 1 2 1 23 9 4 19 2 2 2 ...
$ READMIT.MDC : Factor w/ 18 levels "CIRCULATORY DZ",..: 17 17 7 13 1 14 17 1 17 17 ...
$ READMIT.DRG : Factor w/ 141 levels "100","102","103",..: 19 19 65 127 41 80 18 42 20 21 ...
$ READMIT.DX.CLASF : Factor w/ 195 levels "ABDOMINAL ANEURYSM WITHOUT MENTION OF RUPTURE",..: 126 125 189 117 16 116 51 15 126 161 ...
$ READMIT.ADMITTING.DR: Factor w/ 59 levels (intentionally blank)
$ READMIT.ATTENDING.DR: Factor w/ 59 levels (intentionally blank)
$ READMIT.HOSP.SVC : Factor w/ 8 levels "CCU","MED","MIC",..: 2 2 2 5 2 2 2 2 2 2 ...
根据该数据，我感兴趣的只有两（2）个READMIT.SOURCE ID，"Emergency Unit"和"Transfer from Long Term Care"，原因是798个观察结果中有两个占其中的791个。
起初我尝试subset()这是一个没有beuno。所以现在我做了以下事情：
er <- data.frame(radata[radata$READMIT.SOURCE == "Emergency Unit",])
lt <- data.frame(radata[radata$READMIT.SOURCE == "Transfer from Long Term Care",])
以上两行给了我我需要的东西。我现在的问题是，如何创建一个新的data.frame，它将包含两个新创建的？ er和lt的结构与上面显示的结构完全相同。
谢谢，
答案 0 :(得分：3)
请阅读R的更多教程和介绍，并特别注意子集化。您正在寻找%in%：
radata[radata$READMIT.SOURCE %in% c("Emergency Unit", "Transfer from Long Term Care"),]
当然，您也可以使用两个data.frames并在其上使用rbind。