facet grid using .data pronoun on both formula sides not working-CodePudding

I am trying designing an interactive plot. I want the user to specify the facet_grid formula, however if in both sides of the formula .data pronoun it does not work. Any workaround?

left  <- 'Species'
right <- 'Petal.Width' 

### not working 
ggplot(iris, aes(y = Sepal.Length, x = Sepal.Width))   
  geom_line()   
  facet_grid(.data[[left]] ~ .data[[right]])

### working 
ggplot(iris, aes(y = Sepal.Length, x = Sepal.Width))   
  geom_line()   
  facet_grid(.data[[left]] ~ .)

Here are the R session details

R version 4.0.4 (2021-02-15)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 19044)

Matrix products: default

locale:
[1] LC_COLLATE=English_Israel.1252  LC_CTYPE=English_Israel.1252    LC_MONETARY=English_Israel.1252
[4] LC_NUMERIC=C                    LC_TIME=English_Israel.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] shiny_1.6.0     forcats_0.5.1   stringr_1.4.0   dplyr_1.0.7     purrr_0.3.4     readr_1.4.0    
 [7] tidyr_1.1.4     tibble_3.1.5    ggplot2_3.3.5   tidyverse_1.3.1

CodePudding user response：

Instead of using a formula you could pass the variables to facet by via the vars() quoting function to the rows and cols arguments of facet_grid :

left  <- 'Species'
right <- 'Petal.Width' 

library(ggplot2)

ggplot(iris, aes(y = Sepal.Length, x = Sepal.Width))   
  geom_line()   
  facet_grid(rows = vars(.data[[left]]), cols = vars(.data[[right]]))