aes_string我在使用 ggplot2 编程时使用了一些方便的行为。但aes_string已被弃用（我相信是从 ggplot2 版本 3.4.0 开始）。我正在努力思考如何很好地替换它。
具体来说，我之前创建了通过省略号接受任意字符串参数的函数，并通过 do.call 将这些参数传递给 aes_string，如下面的第一个表示所示。
自从注意到弃用警告以来，我一直试图避免aes_string，并发现自己实际上只是以一种相当“hacky”的方式模仿它。
据推测，无论有什么缺陷aes_string导致其被弃用，也适用于我的黑客解决方法。请参阅第二个代表。
有更优雅的解决方案吗？我想继续将变量名称作为字符串传递。
library(ggplot2)
plotterOld <- function(...) {
args <- list(...)
pointAes <- do.call(aes_string, args = args)
ggplot(mpg, aes(displ, cty)) +
geom_point(mapping = pointAes)
}
plotterOld(colour = "cyl", size = "year")
#> Warning: `aes_string()` was deprecated in ggplot2 3.0.0.
#> ℹ Please use tidy evaluation ideoms with `aes()`
# it can accept NULLs, and e.g. intuitively doesn't map size to anything
plotterOld(colour = "cyl", size = NULL)
# no arguments also works fine
plotterOld()
Created on 2022-11-11 with reprex v2.0.2
library(ggplot2)
# arbitrary aesthetics passed as strings using ellipses, aes, quo and .data
myAesString <- function(...) {
dots <- list(...)
# early exits
stopifnot(rlang::is_named2(dots))
if (length(dots) == 0) {
return(NULL)
}
# initialise empty mapping object and fill it with quosures where appropriate
mapping <- aes()
for (n in names(dots)) {
v <- dots[[n]]
if (!is.null(v)) {
if (!rlang::is_string(v)) stop(n, " must be a string or NULL")
mapping[[n]] <- quo(.data[[v]])
}
}
return(mapping)
}
plotterNew <- function(...) {
pointAes <- myAesString(...)
ggplot(mpg, aes(displ, cty)) +
geom_point(mapping = pointAes)
}
plotterNew(colour = "cyl", size = "year")
plotterNew(colour = "cyl", size = NULL, shape = "drv")
plotterNew()
# seems to work fine
p <- plotterNew(colour = "cyl", size = "year")
p$layers[[1]]$mapping
#> Aesthetic mapping:
#> * `colour` -> `.data[["cyl"]]`
#> * `size` -> `.data[["year"]]`
Created on 2022-11-11 with reprex v2.0.2
Session infosessioninfo::session_info()
#> ─ Session info ───────────────────────────────────────────────────────────────
#> setting value
#> version R version 4.2.1 (2022-06-23)
#> os macOS Big Sur ... 10.16
#> system x86_64, darwin17.0
#> ui X11
#> language (EN)
#> collate en_GB.UTF-8
#> ctype en_GB.UTF-8
#> tz Europe/Amsterdam
#> date 2022-11-11
#> pandoc 2.18 @ /Applications/RStudio.app/Contents/MacOS/quarto/bin/tools/ (via rmarkdown)
#>
#> ─ Packages ───────────────────────────────────────────────────────────────────
#> package * version date (UTC) lib source
#> assertthat 0.2.1 2019-03-21 [1] CRAN (R 4.2.0)
#> cli 3.4.1 2022-09-23 [1] CRAN (R 4.2.0)
#> colorspace 2.0-3 2022-02-21 [1] CRAN (R 4.2.0)
#> curl 4.3.3 2022-10-06 [1] CRAN (R 4.2.0)
#> DBI 1.1.3 2022-06-18 [1] CRAN (R 4.2.0)
#> digest 0.6.30 2022-10-18 [1] CRAN (R 4.2.1)
#> dplyr 1.0.10 2022-09-01 [1] CRAN (R 4.2.0)
#> evaluate 0.18 2022-11-07 [1] CRAN (R 4.2.0)
#> fansi 1.0.3 2022-03-24 [1] CRAN (R 4.2.0)
#> farver 2.1.1 2022-07-06 [1] CRAN (R 4.2.0)
#> fastmap 1.1.0 2021-01-25 [1] RSPM (R 4.2.0)
#> fs 1.5.2 2021-12-08 [1] RSPM (R 4.2.0)
#> generics 0.1.3 2022-07-05 [1] CRAN (R 4.2.0)
#> ggplot2 * 3.4.0 2022-11-04 [1] CRAN (R 4.2.1)
#> glue 1.6.2 2022-02-24 [1] CRAN (R 4.2.0)
#> gtable 0.3.1 2022-09-01 [1] CRAN (R 4.2.0)
#> highr 0.9 2021-04-16 [1] RSPM (R 4.2.0)
#> htmltools 0.5.3 2022-07-18 [1] CRAN (R 4.2.0)
#> httr 1.4.4 2022-08-17 [1] CRAN (R 4.2.0)
#> knitr 1.40 2022-08-24 [1] CRAN (R 4.2.0)
#> labeling 0.4.2 2020-10-20 [1] CRAN (R 4.2.0)
#> lifecycle 1.0.3 2022-10-07 [1] CRAN (R 4.2.0)
#> magrittr 2.0.3 2022-03-30 [1] CRAN (R 4.2.0)
#> mime 0.12 2021-09-28 [1] RSPM (R 4.2.0)
#> munsell 0.5.0 2018-06-12 [1] CRAN (R 4.2.0)
#> pillar 1.8.1 2022-08-19 [1] CRAN (R 4.2.0)
#> pkgconfig 2.0.3 2019-09-22 [1] CRAN (R 4.2.0)
#> purrr 0.3.5 2022-10-06 [1] CRAN (R 4.2.0)
#> R.cache 0.16.0 2022-07-21 [1] CRAN (R 4.2.0)
#> R.methodsS3 1.8.2 2022-06-13 [1] CRAN (R 4.2.0)
#> R.oo 1.25.0 2022-06-12 [1] CRAN (R 4.2.0)
#> R.utils 2.12.1 2022-10-30 [1] CRAN (R 4.2.0)
#> R6 2.5.1 2021-08-19 [1] CRAN (R 4.2.0)
#> reprex 2.0.2 2022-08-17 [1] CRAN (R 4.2.0)
#> rlang 1.0.6 2022-09-24 [1] CRAN (R 4.2.0)
#> rmarkdown 2.18 2022-11-09 [1] CRAN (R 4.2.1)
#> rstudioapi 0.14 2022-08-22 [1] CRAN (R 4.2.0)
#> scales 1.2.1 2022-08-20 [1] CRAN (R 4.2.0)
#> sessioninfo 1.2.2 2021-12-06 [1] RSPM (R 4.2.0)
#> stringi 1.7.8 2022-07-11 [1] CRAN (R 4.2.0)
#> stringr 1.4.1 2022-08-20 [1] CRAN (R 4.2.0)
#> styler 1.8.1 2022-11-07 [1] CRAN (R 4.2.0)
#> tibble 3.1.8 2022-07-22 [1] CRAN (R 4.2.0)
#> tidyselect 1.2.0 2022-10-10 [1] CRAN (R 4.2.0)
#> utf8 1.2.2 2021-07-24 [1] CRAN (R 4.2.0)
#> vctrs 0.5.0 2022-10-22 [1] CRAN (R 4.2.0)
#> withr 2.5.0 2022-03-03 [1] CRAN (R 4.2.0)
#> xfun 0.34 2022-10-18 [1] CRAN (R 4.2.0)
#> xml2 1.3.3 2021-11-30 [1] RSPM (R 4.2.0)
#> yaml 2.3.6 2022-10-18 [1] CRAN (R 4.2.1)
#>
#> [1] /Library/Frameworks/R.framework/Versions/4.2/Resources/library
#>
#> ──────────────────────────────────────────────────────────────────────────────
一种选择是将带引号的字符串列表转换为符号，使用sym:
library(ggplot2)
plotterOld <- function(...) {
args <- lapply(list(...), function(x) if (!is.null(x)) sym(x))
pointAes <- do.call(aes, args = args)
ggplot(mpg, aes(displ, cty)) +
geom_point(mapping = pointAes)
}
UPDATE我们可以通过使用进一步简化!!!摆脱do.call:
plotterOld <- function(...) {
args <- lapply(list(...), function(x) if (!is.null(x)) sym(x))
ggplot(mpg, aes(displ, cty)) +
geom_point(mapping = aes(!!!args))
}
plotterOld(colour = "cyl", size = "year")
plotterOld(colour = "cyl", size = NULL)
plotterOld()
