我认为在 tidyeval 框架中执行此操作的“预期”方法是将参数作为名称(而不是字符串)输入,然后使用引用参数enquo()
. ggplot2
了解整洁的评估运算符,因此这适用于ggplot2
以及。
首先,让我们调整一下dplyr
您的示例中的摘要函数:
library(tidyverse)
library(rlang)
get_means <- function(df, metric, group) {
metric = enquo(metric)
group = enquo(group)
df %>%
group_by(!!group) %>%
summarise(!!paste0("mean_", as_label(metric)) := mean(!!metric))
}
get_means(cats, weight, type)
type mean_weight
1 fat 20.0
2 not_fat 10.2
get_means(iris, Petal.Width, Species)
Species mean_Petal.Width
1 setosa 0.246
2 versicolor 1.33
3 virginica 2.03
现在添加到ggplot中:
get_means <- function(df, metric, group) {
metric = enquo(metric)
group = enquo(group)
df %>%
group_by(!!group) %>%
summarise(mean_stat = mean(!!metric)) %>%
ggplot(aes(!!group, mean_stat)) +
geom_point()
}
get_means(cats, weight, type)
我不确定您想要什么类型的图,但您可以使用整洁的评估来绘制数据和汇总值。例如:
plot_func = function(data, metric, group) {
metric = enquo(metric)
group = enquo(group)
data %>%
ggplot(aes(!!group, !!metric)) +
geom_point() +
geom_point(data=. %>%
group_by(!!group) %>%
summarise(!!metric := mean(!!metric)),
shape="_", colour="red", size=8) +
expand_limits(y=0) +
scale_y_continuous(expand=expand_scale(mult=c(0,0.02)))
}
plot_func(cats, weight, type)
仅供参考,您可以使用以下命令允许函数采用任意数量的分组变量(包括无)...
论证和enquos
代替enquo
(这还需要使用!!!
(取消引号拼接)而不是!!
(取消引用))。
get_means <- function(df, metric, ...) {
metric = enquo(metric)
groups = enquos(...)
df %>%
group_by(!!!groups) %>%
summarise(!!paste0("mean_", quo_text(metric)) := mean(!!metric))
}
get_means(mtcars, mpg, cyl, vs)
cyl vs mean_mpg
1 4 0 26
2 4 1 26.7
3 6 0 20.6
4 6 1 19.1
5 8 0 15.1
get_means(mtcars, mpg)
mean_mpg
1 20.1