gnu: Add r-survival.

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

gnu/packages/statistics.scm

@@ -3230,6 +3230,26 @@ distribution).")
 classification, regression and survival trees.")
     (license (list license:gpl2+ license:gpl3+))))
 
+(define-public r-survival
+  (package
+    (name "r-survival")
+    (version "2.40-1")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (cran-uri "survival" version))
+       (sha256
+        (base32
+         "10pf0kq0g66k5rgizrvh29mq3r84acljw2jgrv5yp6z38xw23mci"))))
+    (build-system r-build-system)
+    (home-page "https://github.com/therneau/survival")
+    (synopsis "Survival analysis")
+    (description
+     "This package contains the core survival analysis routines, including
+definition of Surv objects, Kaplan-Meier and Aalen-Johansen (multi-state)
+curves, Cox models, and parametric accelerated failure time models.")
+    (license license:lgpl2.0+)))
+
 (define-public r-hmisc
   (package
     (name "r-hmisc")