Question

我在R中有以下最小例子：

testing = data.frame(c("Once a week", "Once a week", "Rarely", "Once a month", "Once a month"), c("Once a month", "Once a month", "Once a week", "Rarely", "Rarely"))
colnames(testing) = c("one", "two")
testing

        one          two
1  Once a week Once a month
2  Once a week Once a month
3       Rarely  Once a week
4 Once a month       Rarely
5 Once a month       Rarely

我希望最终结果是一个数据框，其中一列中包含所有可能的分类因子，其余列是每个列/变量的计数，如下所示：

categories    one    two
Rarely        1      2
Once a month  2      2
Once a week   2      1

我对R库没有任何限制，所以这里最简单的是什么（可能是plyr / dplyr？）。

感谢。

Answer 1

表无需外部包即可使用：

sapply(testing, table)
#             one two
#Once a month   2   2
#Once a week    2   1
#Rarely         1   2

Answer 2

您可以使用tidyr和dplyr个包来整理您的表格，并使用基本table函数计算类别

testing = data.frame(c("Once a week", "Once a week", "Rarely", "Once a month", "Once a month"), c("Once a month", "Once a month", "Once a week", "Rarely", "Rarely"))
colnames(testing) = c("one", "two")
testing
#>            one          two
#> 1  Once a week Once a month
#> 2  Once a week Once a month
#> 3       Rarely  Once a week
#> 4 Once a month       Rarely
#> 5 Once a month       Rarely

library(tidyr)
library(dplyr)

testing %>%
  gather("type", "categories") %>%
  table()
#>      categories
#> type  Once a month Once a week Rarely
#>   one            2           2      1
#>   two            2           1      2

# or reorder colum before table
testing %>%
  gather("type", "categories") %>%
  select(categories, type) %>%
  table()
#>               type
#> categories     one two
#>   Once a month   2   2
#>   Once a week    2   1
#>   Rarely         1   2

Answer 3

以下是利用tidyr::gather，tidyr::spread和dplyr::count的另一种方式：

library(dplyr)
library(tidyr)

testing %>%
  gather(measure, value) %>%
  count(measure, value) %>%
  spread(measure, n)

# Source: local data frame [3 x 3]
# 
#          value   one   two
#          (chr) (int) (int)
# 1 Once a month     2     2
# 2  Once a week     2     1
# 3       Rarely     1     2

此外，请参阅此fantastic gist有关此主题的内容。

获取R中多个变量/列的分类因子计数

3 个答案: