gnu: Add r-gld.

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

gnu/packages/statistics.scm

@@ -6721,3 +6721,36 @@ of L-moments and trimmed L-moments of distributions and data samples;
 parameter estimation; L-moment ratio diagram; plot vs.  quantiles of an
 extreme-value distribution.")
     (license license:cpl1.0)))
+
+(define-public r-gld
+  (package
+    (name "r-gld")
+    (version "2.6.2")
+    (source
+      (origin
+        (method url-fetch)
+        (uri (cran-uri "gld" version))
+        (sha256
+          (base32 "1wrw7i5bq7rb2ahadm57y9fmr697r7lp9ln7ajcd592b0nn60n4i"))))
+    (properties `((upstream-name . "gld")))
+    (build-system r-build-system)
+    (propagated-inputs `(("r-e1071" ,r-e1071) ("r-lmom" ,r-lmom)))
+    (home-page
+      "https://cran.r-project.org/package=gld")
+    (synopsis
+      "Estimation and Use of the Generalised (Tukey) Lambda Distribution")
+    (description
+      "The generalised lambda distribution, or Tukey lambda distribution,
+provides a wide variety of shapes with one functional form.  This package
+provides random numbers, quantiles, probabilities, densities and
+density quantiles for four different types of the distribution, the FKML
+(Freimer et al 1988), RS (Ramberg and Schmeiser 1974), GPD (van Staden
+and Loots 2009) and FM5 - see documentation for details.  It provides the
+density function, distribution function, and Quantile-Quantile plots.
+It implements a variety of estimation methods for the distribution,
+including diagnostic plots.  Estimation methods include the starship (all
+4 types), method of L-Moments for the GPD and FKML types, and a number
+of methods for only the FKML type.  These include maximum likelihood,
+maximum product of spacings, Titterington's method, Moments, Trimmed
+L-Moments and Distributional Least Absolutes.")
+    (license license:gpl2+)))