add https://r-graphics.org

diff --git a/r.mdwn b/r.mdwn
index 3949e97..7c4f908 100644 (file)
--- a/r.mdwn
+++ b/r.mdwn
@@ -1,3 +1,5 @@
+https://r-graphics.org
+

 Inspired by https://canvas.harvard.edu/courses/5749/assignments/syllabus (STAT E-100, Fall 2015)
 
     > options(warn=-1) # warnings from `library` are annoying
 Inspired by https://canvas.harvard.edu/courses/5749/assignments/syllabus (STAT E-100, Fall 2015)
 
     > options(warn=-1) # warnings from `library` are annoying