r-dplyr:为向量中的每个变量名添加summary中的新变量

Question

我有这段代码：

trimmedMeans <- cleaned %>%
filter(TrackName == t & ToBeTrimmed != 1) %>%
group_by(TrackName, SpeakerName) %>%
summarise(Expectation.Mean = mean(Expectation, na.rm = TRUE),
Expectation.Sd = sd(Expectation, na.rm = TRUE),
Interesting.Mean = mean(Interesting, na.rm = TRUE),
Interesting.Sd = sd(Interesting, na.rm = TRUE),
Useful.Mean = mean(Useful, na.rm = TRUE),
Useful.Sd = sd(Useful, na.rm = TRUE),
OralPresentation.Mean = mean(OralPresentation, na.rm = TRUE),
OralPresentation.Sd = sd(OralPresentation, na.rm = TRUE),
NumOfVoters = n()
)

现在假设有这个向量：

myvars <- c("Expectation", "Interesting", "Useful", "OralPresentation")

我想动态地使用向量myvars来概括前面的代码块。

Answer 1

有一个summarise_at就是这样的：

iris
%>% group_by(Species)
%>% summarise_at(c("Sepal.Length", "Sepal.Width"), funs(mean, sd), na.rm=TRUE)
# A tibble: 3 x 5
Species    Sepal.Length_mean Sepal.Width_mean Sepal.Length_sd Sepal.Width_sd
<fct>                  <dbl>            <dbl>           <dbl>          <dbl>
1 setosa                  5.01             3.43           0.352          0.379
2 versicolor              5.94             2.77           0.516          0.314
3 virginica               6.59             2.97           0.636          0.322