distro: Add GSL.

* distro/packages/algebra.scm (gsl): New variable.

distro/packages/algebra.scm

@@ -1,5 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2012 Andreas Enge <andreas@enge.fr>
+;;; Copyright © 2013 Ludovic Courtès <ludo@gnu.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -74,3 +75,29 @@ multiplication routines such as Toom–Cook and the FFT. ")
 solve the shortest vector problem.")
    (license lgpl2.1+)
    (home-page "http://perso.ens-lyon.fr/damien.stehle/fplll/")))
+
+(define-public gsl
+  (package
+    (name "gsl")
+    (version "1.15")
+    (source
+     (origin
+      (method url-fetch)
+      (uri (string-append "mirror://gnu/gsl/gsl-"
+                          version ".tar.gz"))
+      (sha256
+       (base32
+        "18qf6jzz1r3mzb5qynywv4xx3z9g61hgkbpkdrhbgqh2g7jhgfc5"))))
+    (build-system gnu-build-system)
+    (home-page "http://www.gnu.org/software/gsl/")
+    (synopsis "The GNU Scientific Library, a large numerical library")
+    (description
+     "The GNU Scientific Library (GSL) is a numerical library for C
+and C++ programmers.  It is free software under the GNU General
+Public License.
+
+The library provides a wide range of mathematical routines such
+as random number generators, special functions and least-squares
+fitting.  There are over 1000 functions in total with an
+extensive test suite.")
+    (license gpl3+)))