label_parsed doesn't render the expression

[sahirbhatnagar]

This example from the help docs used to work, but doesn't anymore.

library(ggplot2)
mtcars$cyl2 <- factor(mtcars$cyl, labels = c("alpha", "beta", "gamma"))
p <- ggplot(mtcars, aes(wt, mpg)) + geom_point()
p + facet_grid(. ~ cyl2, labeller = label_parsed)

Session info

devtools::session_info()
#> Session info -------------------------------------------------------------
#>  setting  value                       
#>  version  R version 3.4.1 (2017-06-30)
#>  system   x86_64, linux-gnu           
#>  ui       X11                         
#>  language en_US                       
#>  collate  en_US.UTF-8                 
#>  tz       Canada/Eastern              
#>  date     2017-10-02
#> Packages -----------------------------------------------------------------
#>  package    * version    date       source                          
#>  backports    1.1.0      2017-05-22 cran (@1.1.0)                   
#>  base       * 3.4.1      2017-07-08 local                           
#>  bitops       1.0-6      2013-08-17 CRAN (R 3.4.1)                  
#>  colorspace   1.3-2      2016-12-14 CRAN (R 3.4.1)                  
#>  compiler     3.4.1      2017-07-08 local                           
#>  datasets   * 3.4.1      2017-07-08 local                           
#>  devtools     1.13.3     2017-08-02 CRAN (R 3.4.1)                  
#>  digest       0.6.12     2017-01-27 CRAN (R 3.4.1)                  
#>  evaluate     0.10.1     2017-06-24 cran (@0.10.1)                  
#>  ggplot2    * 2.2.1.9000 2017-09-18 Github (hadley/ggplot2@c592e32) 
#>  graphics   * 3.4.1      2017-07-08 local                           
#>  grDevices  * 3.4.1      2017-07-08 local                           
#>  grid         3.4.1      2017-07-08 local                           
#>  gtable       0.2.0      2016-02-26 CRAN (R 3.4.1)                  
#>  htmltools    0.3.6      2017-04-28 cran (@0.3.6)                   
#>  knitr        1.17       2017-08-10 cran (@1.17)                    
#>  labeling     0.3        2014-08-23 CRAN (R 3.4.1)                  
#>  lazyeval     0.2.0      2016-06-12 CRAN (R 3.4.1)                  
#>  magrittr     1.5        2014-11-22 CRAN (R 3.4.1)                  
#>  memoise      1.1.0      2017-04-21 CRAN (R 3.4.1)                  
#>  methods    * 3.4.1      2017-07-08 local                           
#>  munsell      0.4.3      2016-02-13 CRAN (R 3.4.1)                  
#>  plyr         1.8.4      2016-06-08 CRAN (R 3.4.1)                  
#>  Rcpp         0.12.12    2017-07-15 CRAN (R 3.4.1)                  
#>  RCurl        1.95-4.8   2016-03-01 CRAN (R 3.4.1)                  
#>  reshape2     1.4.2      2016-10-22 CRAN (R 3.4.1)                  
#>  rlang        0.1.2      2017-08-09 CRAN (R 3.4.1)                  
#>  rmarkdown    1.6        2017-06-15 CRAN (R 3.4.1)                  
#>  rprojroot    1.2        2017-01-16 CRAN (R 3.4.1)                  
#>  scales       0.5.0.9000 2017-09-18 Github (hadley/scales@d767915)  
#>  stats      * 3.4.1      2017-07-08 local                           
#>  stringi      1.1.5      2017-04-07 CRAN (R 3.4.1)                  
#>  stringr      1.2.0      2017-02-18 CRAN (R 3.4.1)                  
#>  tibble       1.3.4      2017-08-22 CRAN (R 3.4.1)                  
#>  tools        3.4.1      2017-07-08 local                           
#>  utils      * 3.4.1      2017-07-08 local                           
#>  withr        2.0.0      2017-09-18 Github (jimhester/withr@d1f0957)
#>  XML          3.98-1.9   2017-06-19 CRAN (R 3.4.1)                  
#>  yaml         2.1.14     2016-11-12 cran (@2.1.14)

[hadley]

Seems to be a problem in title_spec. When the labeller yield expressions in build_strip(), need to pass label[[1]] instead of label to the textGrob.

[hadley]

And the base problem is that apply() indexes with [, not [[

mat <- matrix(1:4, nrow = 2)
lmt <- matrix(as.list(1:4), nrow = 2)

apply(mat, c(1,2), typeof)
#>      [,1]      [,2]     
#> [1,] "integer" "integer"
#> [2,] "integer" "integer"
apply(lmt, c(1,2), typeof)
#>      [,1]   [,2]  
#> [1,] "list" "list"
#> [2,] "list" "list"