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试图编写一个相对简单的包装器来生成一些图，但无法弄清楚如何指定分组变量的整洁评估，该分组变量指定为...一个示例函数，该函数对变量进行分面但不通过分组进行区分......

my_plot <- function(df = starwars,
                    select = c(height, mass),
                    ...){
    results <- list()
    ## Tidyeval arguments
    quo_select <- enquo(select)
    quo_group  <- quos(...)
    ## Filter, reshape and plot
    results$df <- df %>%
                  dplyr::filter(!is.na(!!!quo_group)) %>%
                  dplyr::select(!!quo_select, !!!quo_group) %>%
                  gather(key = variable, value = value, !!!quo_select) %>% 
                  ## Specify what to plot
                  ggplot(aes(value)) +
                  geom_histogram(stat = 'count')  +
                  facet_wrap(~variable, scales = 'free', strip.position = 'bottom')
    return(results)
}
## Plot height and mass as facets but colour histograms by hair_color
my_plot(df = starwars, select = c(height, mass), hair_color)

很好用，但是如何区分不同的hair_color？通常这是在内部完成的，aes()但由于这是使用quos()（即quo_group）我应该（我认为）aes_()使用的结果

my_plot <- function(df = starwars,
                    select = c(height, mass),
                    ...){
    results <- list()
    ## Tidyeval arguments
    quo_select <- enquo(select)
    quo_group  <- quos(...)
    ## Filter, reshape and plot
    results$df <- df %>%
                  dplyr::filter(!is.na(!!!quo_group)) %>%
                  dplyr::select(!!quo_select, !!!quo_group) %>%
                  gather(key = variable, value = value, !!!quo_select) %>% 
                  ## Specify what to plot, including colouring by the supplied ... groupings
                  ggplot(aes_(~value, colour = !!!quo_group)) + 
                  geom_histogram(stat = 'count')  +
                  facet_wrap(~variable, scales = 'free', strip.position = 'bottom')
    return(results)
}
## Plot height and mass as facets but colour histograms by hair_color
my_plot(df = starwars, select = c(height, mass), hair_color)
Error in !quo_group : invalid argument type

我现在看不到或解决了多次阅读dplyr 编程的错误。

谁能指出我的错误/给我指路？

4

2 回答 2

3

新发布的ggplot2 v3.0.0支持!!inside aes()。通过一些小的修改，您的功能现在可以工作了

library(tidyverse)

my_plot <- function(df = starwars,
                    select = c(height, mass),
                    ...){
  results <- list()

  ## Tidyeval arguments
  quo_select <- enquo(select)

  # only need quo here, if quos is used then we need to `unlist` to 
  # convert its output from list to vector
  quo_group  <- quo(...) 

  ## Filter, reshape and plot
  results$df <- df %>%
    dplyr::filter(!is.na(!!!quo_group)) %>%
    dplyr::select(!!quo_select, !!!quo_group) %>%
    gather(key = variable, value = value, !!!quo_select) %>% 
    ## Specify what to plot, including coloring by the supplied dots `...` 
    ggplot(aes(value, color = !!quo_group, fill = !!quo_group)) +  # unquote inside aes
    geom_histogram(stat = 'count')  +
    facet_wrap(vars(variable), scales = 'free', strip.position = 'bottom')
  return(results)
}

## Plot height and mass as facets but color histograms by hair_color
my_plot(df = starwars, select = c(height, mass), hair_color)

由reprex 包（v0.2.0.9000）于 2018 年 9 月 12 日创建。

于 2018-09-12T13:28:13.890 回答
1

我不确定我是否理解这个问题。这是否满足要求？

library(ggplot2)
library(data.table)

your_plot <- function(df, select, color=NULL) {

  df <- as.data.table(df)[, mget(na.omit(c(select, color)))]

  ggplot(melt(df, color, select), aes_string(x=quote(value), color=color)) +
    geom_histogram(stat="count") +
    facet_wrap(~variable, scales="free", strip.position="bottom")

}

your_plot(dplyr::starwars, c("height", "mass"), "hair_color")

这用于melt堆叠select变量，color每个堆栈重复变量。它还使用aes_string, sinceaes(x=value, color=color)失败时color=NULL。

于 2018-02-08T04:03:32.703 回答