gnu: Add r-vipor.

* gnu/packages/statistics.scm (r-vipor): New variable.

gnu/packages/statistics.scm

@@ -3815,3 +3815,22 @@ (define-public r-ztable
 @code{glm}, @code{coxph}, @code{nls}, @code{fitdistr}, @code{mytable} and
 @code{cbind.mytable} objects.")
     (license license:gpl2+)))
+
+(define-public r-vipor
+  (package
+    (name "r-vipor")
+    (version "0.4.4")
+    (source (origin
+              (method url-fetch)
+              (uri (cran-uri "vipor" version))
+              (sha256
+               (base32
+                "0p1z9a3fazl78pj8a1i2n62v8hrs8cinq82j9wpawhmfkn3dggss"))))
+    (build-system r-build-system)
+    (home-page "http://cran.r-project.org/web/packages/vipor")
+    (synopsis "Plot categorical data using noise and density estimates")
+    (description
+     "This package provides tools to generate a violin point plot, a
+combination of a violin/histogram plot and a scatter plot by offsetting points
+within a category based on their density using quasirandom noise.")
+    (license license:gpl2+)))