How to format selected axis text words with italic and bold using ggtext

Question

Any guidance on getting bold and italic formatted axis text using ggtext would be appreciated.

Possibly a problem due to my set up or is something missing?

What I've tried

library(ggplot2)
library(ggtext)


df1 <- data.frame(var1 = c("italic text",
                           "bold text"),
                  var2 = 1:2)

# neither of the formatting options on offer in ggtext seem to work:


var_lab_mkd = c("*italic* text",
                   "**bold** text")

var_lab_css = c("<i>italic</i> text",
                   "<b>bold</b> text")

ggplot(df1, aes(var2, var1))+
  geom_col()+
  scale_y_discrete(labels = var_lab_mkd)+
  # scale_y_discrete(labels = var_lab_css)+
  theme(axis.text.y.left = element_markdown())+
  labs(title = "Axis text formating not working")

This results in:

What I would like, but using ggtext

var_lab_exp = c(expression(italic(italic)~text),
                expression(bold(bold)~text))

ggplot(df1, aes(var2, var1))+
  geom_col()+
  scale_y_discrete(labels = var_lab_exp)+
  labs(title = "Axis text formated as desired")

R session information

R version 4.2.0 (2022-04-22 ucrt)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 19044)

Matrix products: default

locale:
[1] LC_COLLATE=English_United Kingdom.utf8 
[2] LC_CTYPE=English_United Kingdom.utf8   
[3] LC_MONETARY=English_United Kingdom.utf8
[4] LC_NUMERIC=C                           
[5] LC_TIME=English_United Kingdom.utf8    

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

other attached packages:
[1] reprex_2.0.1  ggtext_0.1.1  ggplot2_3.3.5

loaded via a namespace (and not attached):
 [1] Rcpp_1.0.8.3      highr_0.9         pillar_1.7.0      compiler_4.2.0   
 [5] R.utils_2.11.0    R.methodsS3_1.8.1 tools_4.2.0       digest_0.6.29    
 [9] evaluate_0.15     lifecycle_1.0.1   tibble_3.1.6      gtable_0.3.0     
[13] R.cache_0.15.0    pkgconfig_2.0.3   rlang_1.0.2       rstudioapi_0.13  
[17] cli_3.3.0         yaml_2.3.5        xfun_0.30         fastmap_1.1.0    
[21] knitr_1.38        withr_2.5.0       dplyr_1.0.8       stringr_1.4.0    
[25] styler_1.7.0      xml2_1.3.3        generics_0.1.2    vctrs_0.4.1      
[29] fs_1.5.2          grid_4.2.0        gridtext_0.1.4    tidyselect_1.1.2 
[33] glue_1.6.2        R6_2.5.1          processx_3.5.3    fansi_1.0.3      
[37] rmarkdown_2.14    callr_3.7.0       clipr_0.8.0       purrr_0.3.4      
[41] farver_2.1.0      magrittr_2.0.3    ps_1.7.0          htmltools_0.5.2  
[45] scales_1.2.0      ellipsis_0.3.2    colorspace_2.0-3  labeling_0.4.2   
[49] utf8_1.2.2        stringi_1.7.6     munsell_0.5.0     markdown_1.1     
[53] crayon_1.5.1      R.oo_1.24.0  

Answer 1

When I run your first code for both formatting, it seems to work:

library(ggplot2)
library(ggtext)


df1 <- data.frame(var1 = c("italic text",
                           "bold text"),
                  var2 = 1:2)

# neither of the formatting options on offer in ggtext seem to work:


var_lab_mkd = c("*italic* text",
                "**bold** text")

var_lab_css = c("<i>italic</i> text",
                "<b>bold</b> text")

ggplot(df1, aes(var2, var1))+
  geom_col()+
  scale_y_discrete(labels = var_lab_mkd)+
  # scale_y_discrete(labels = var_lab_css)+
  theme(axis.text.y.left = element_markdown())+
  labs(title = "Axis text formating not working")

Output:

The text is bold and italic.

library(ggplot2)
library(ggtext)


df1 <- data.frame(var1 = c("italic text",
                           "bold text"),
                  var2 = 1:2)

# neither of the formatting options on offer in ggtext seem to work:


var_lab_mkd = c("*italic* text",
                "**bold** text")

var_lab_css = c("<i>italic</i> text",
                "<b>bold</b> text")

ggplot(df1, aes(var2, var1))+
  geom_col()+
  #scale_y_discrete(labels = var_lab_mkd)+
  scale_y_discrete(labels = var_lab_css)+
  theme(axis.text.y.left = element_markdown())+
  labs(title = "Axis text formating not working")

Output:

As you can see both formating works.

My sessionInfo:

R version 4.1.0 (2021-05-18)
Platform: x86_64-apple-darwin17.0 (64-bit)
Running under: macOS 12.3.1

Matrix products: default
LAPACK: /Library/Frameworks/R.framework/Versions/4.1/Resources/lib/libRlapack.dylib

locale:
[1] nl_NL.UTF-8/nl_NL.UTF-8/nl_NL.UTF-8/C/nl_NL.UTF-8/nl_NL.UTF-8

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

other attached packages:
 [1] ggtext_0.1.1      lubridate_1.8.0   data.table_1.14.2 sjmisc_2.8.9      fpp_0.5           tseries_0.10-49   lmtest_0.9-39     zoo_1.8-9        
 [9] expsmooth_2.3     fma_2.4           forecast_8.16     forcats_0.5.1     stringr_1.4.0     dplyr_1.0.8       purrr_0.3.4       readr_2.1.2      
[17] tidyr_1.2.0       tibble_3.1.6      ggplot2_3.3.5     tidyverse_1.3.1   mapview_2.10.0   

loaded via a namespace (and not attached):
  [1] utf8_1.2.2           tidyselect_1.1.2     htmlwidgets_1.5.4    grid_4.1.0           pROC_1.18.0          devtools_2.4.3       munsell_0.5.0       
  [8] codetools_0.2-18     units_0.8-0          future_1.24.0        withr_2.5.0          colorspace_2.0-3     knitr_1.37           uuid_1.0-4          
 [15] rstudioapi_0.13      stats4_4.1.0         wk_0.6.0             ggsignif_0.6.3       TTR_0.24.3           listenv_0.8.0        labeling_0.4.2      
 [22] ggplotgui_1.0.0      plotROC_2.2.1        farver_2.1.0         rprojroot_2.0.2      parallelly_1.30.0    vctrs_0.4.0          generics_0.1.2      
 [29] ipred_0.9-12         xfun_0.30            markdown_1.1         R6_2.5.1             ggiraph_0.8.2        flexmix_2.3-17       cachem_1.0.6        
 [36] assertthat_0.2.1     promises_1.2.0.1     scales_1.1.1         nnet_7.3-17          gtable_0.3.0         globals_0.14.0       processx_3.5.2      
 [43] timeDate_3043.102    rlang_1.0.2          systemfonts_1.0.4    splines_4.1.0        rstatix_0.7.0        rgdal_1.5-28         lazyeval_0.2.2      
 [50] ModelMetrics_1.2.2.2 broom_0.7.12         s2_1.0.7             abind_1.4-5          yaml_2.3.5           reshape2_1.4.4       modelr_0.1.8        
 [57] crosstalk_1.2.0      backports_1.4.1      rsconnect_0.8.25     httpuv_1.6.5         quantmod_0.4.18      gridtext_0.1.4       caret_6.0-90        
 [64] tools_4.1.0          lava_1.6.10          usethis_2.1.5        ellipsis_0.3.2       raster_3.5-15        RColorBrewer_1.1-2   proxy_0.4-26        
 [71] sessioninfo_1.2.2    Rcpp_1.0.8.3         plyr_1.8.6           base64enc_0.1-3      classInt_0.4-3       ps_1.6.0             prettyunits_1.1.1   
 [78] ggpubr_0.4.0         rpart_4.1.16         fracdiff_1.5-1       haven_2.4.3          fs_1.5.2             leafem_0.1.6         magrittr_2.0.3      
 [85] SparseM_1.81         reprex_2.0.1         pkgload_1.2.4        hms_1.1.1            mime_0.12            evaluate_0.15        xtable_1.8-4        
 [92] leaflet_2.0.3.9000   readxl_1.3.1         testthat_3.1.2       compiler_4.1.0       mice_3.14.0          KernSmooth_2.23-20   crayon_1.5.1        
 [99] htmltools_0.5.2      mgcv_1.8-39          later_1.3.0          tzdb_0.2.0           DBI_1.1.2            sjlabelled_1.1.8     dbplyr_2.1.1        
[106] MASS_7.3-55          sf_1.0-7             car_3.0-12           Matrix_1.4-0         brio_1.1.3           cli_3.2.0            quadprog_1.5-8      
[113] parallel_4.1.0       insight_0.17.0       gower_1.0.0          pkgconfig_2.0.3      sp_1.4-6             terra_1.5-21         plotly_4.10.0       
[120] recipes_0.2.0        xml2_1.3.3           foreach_1.5.2        hardhat_0.2.0        webshot_0.5.2        prodlim_2019.11.13   rvest_1.0.2         
[127] snakecase_0.11.0     callr_3.7.0          digest_0.6.29        rmarkdown_2.13       cellranger_1.1.0     curl_4.3.2           shiny_1.7.1         
[134] urca_1.3-0           satellite_1.0.4      modeltools_0.2-23    lifecycle_1.0.1      nlme_3.1-155         jsonlite_1.8.0       carData_3.0-5       
[141] desc_1.4.1           viridisLite_0.4.0    fansi_1.0.3          pillar_1.7.0         lattice_0.20-45      fastmap_1.1.0        httr_1.4.2          
[148] pkgbuild_1.3.1       survival_3.3-1       glue_1.6.2           xts_0.12.1           remotes_2.4.2        png_0.1-7            iterators_1.0.14    
[155] class_7.3-20         stringi_1.7.6        memoise_2.0.1        e1071_1.7-9          future.apply_1.8.1