如何从R变量中的表函数中提取计数等于一个数字的变量?

如何从R变量中的表函数中提取计数等于一个数字的变量?,r,R,我有如下数据: > head(ct) .id x Freq 1 PT_HIGH 0 9650 2 PT_HIGH 1 544 3 C_HIGH 0 7698 4 C_HIGH 1 2496 5 EOB1 1 9351 6 EOB1 2 816 > table(ct$.id) C_HIGH C_SCORE DCCT_DN EOB1 EOB10 EOB11 EOB12 EOB13 2 15

我有如下数据:

> head(ct)
  .id x Freq
1 PT_HIGH 0 9650
2 PT_HIGH 1  544
3  C_HIGH 0 7698
4  C_HIGH 1 2496
5    EOB1 1 9351
6    EOB1 2  816
> table(ct$.id)

  C_HIGH  C_SCORE  DCCT_DN     EOB1    EOB10    EOB11    EOB12    EOB13 
       2       15        2        2        2        2        2        2 
   EOB14    EOB15     EOB2     EOB3     EOB4     EOB5     EOB6     EOB7 
       2        2        2        2        2        2        2        2 
    EOB8     EOB9    EOC2L    EOC2R    EOC3L    EOC3R    EOC4L    EOC4R 
       2        2        2        2        3        3        3        3 
   EOC5L    EOC5R    EOCAL    EOCAR   EOCB1L   EOCB1R   EOCB2L   EOCB2R 
       3        3        2        2        1        1        1        1 
  EOCB3L   EOCB3R   EOCB4L   EOCB4R   EOCB5L   EOCB5R  PT_HIGH PT_SCORE 
       1        1        1        1        1        1        2       16 
  SUMAMP  SUMFOOT   SUMLEG 
       1        3        1 

我可以在R中对它们执行如下表函数:

> head(ct)
  .id x Freq
1 PT_HIGH 0 9650
2 PT_HIGH 1  544
3  C_HIGH 0 7698
4  C_HIGH 1 2496
5    EOB1 1 9351
6    EOB1 2  816
> table(ct$.id)

  C_HIGH  C_SCORE  DCCT_DN     EOB1    EOB10    EOB11    EOB12    EOB13 
       2       15        2        2        2        2        2        2 
   EOB14    EOB15     EOB2     EOB3     EOB4     EOB5     EOB6     EOB7 
       2        2        2        2        2        2        2        2 
    EOB8     EOB9    EOC2L    EOC2R    EOC3L    EOC3R    EOC4L    EOC4R 
       2        2        2        2        3        3        3        3 
   EOC5L    EOC5R    EOCAL    EOCAR   EOCB1L   EOCB1R   EOCB2L   EOCB2R 
       3        3        2        2        1        1        1        1 
  EOCB3L   EOCB3R   EOCB4L   EOCB4R   EOCB5L   EOCB5R  PT_HIGH PT_SCORE 
       1        1        1        1        1        1        2       16 
  SUMAMP  SUMFOOT   SUMLEG 
       1        3        1 

如何仅输出count=2的变量。因此,这些变量将是:C_HIGH,DCCT_DN,EOB1,EOB10…

一个基本R选项正在使用
子集,例如

> subset(names(v), v == 2)
[1] "b" "g" "i" "w"
数据

set.seed(1)
v <- table(sample(letters, 50, replace = TRUE))
set.seed(1)
v