added check_packages.R script

check_packages.R

@@ -0,0 +1,16 @@
+## check_packages.R
+
+#Run this script to check for packages that the other R scripts will use. If missing, try to install.
+#code borrowed from here:
+#http://www.vikram-baliga.com/blog/2015/7/19/a-hassle-free-way-to-verify-that-r-packages-are-installed-and-loaded
+
+#add new packages to the chain here
+packages = c("xml2","rlist","here","magrittr","ggplot2","dplyr","tibble","stringr","readr",
+             "googlesheets","htmltab","DiagrammeR","wrswoR","reshape2")
+
+package.check <- lapply(packages, FUN = function(x) {
+  if (!require(x, character.only = TRUE)) {
+    install.packages(x, dependencies = TRUE)
+    library(x, character.only = TRUE)
+  }
+})