added missing package install

Author: diekhans

install_R_packages.R

@@ -1,11 +1,12 @@
-library(devtools)
-
 # functions to install a package if it's missing
 install_if_missing <- function(package) {
   if (!requireNamespace(package, quietly = TRUE)) {
     install.packages(package)
   }
 }
+
+install_if_missing("devtools")
+
 install_github_if_missing <- function(package, repo) {
   if (!requireNamespace(package, quietly = TRUE)) {
     devtools::install_github(repo)
@@ -20,6 +21,7 @@ packages <- c(
   "devtools",
   "dplyr",
   "ggplot2",
+  "ggplotify",
   "ggpointdensity",
   "ggprism",
   "ggpubr",