gnu: Add r-tensora.

* gnu/packages/cran.scm (r-tensora): New variable.

gnu/packages/cran.scm

@@ -10976,3 +10976,26 @@ instrumental variables models, Analysis of Multivariate Ordinal survey data
 with scale usage heterogeneity, and Bayesian Analysis of Aggregate Random
 Coefficient Logit Models.")
     (license license:gpl2+)))
+
+(define-public r-tensora
+  (package
+    (name "r-tensora")
+    (version "0.36.1")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (cran-uri "tensorA" version))
+       (sha256
+        (base32
+         "176hjy3bvg3in62r97wxbhq187sjz6c1gwy9x6spaxl6k4my3zy7"))))
+    (properties `((upstream-name . "tensorA")))
+    (build-system r-build-system)
+    (home-page "http://www.stat.boogaart.de/tensorA")
+    (synopsis "Advanced tensor arithmetic with named indices")
+    (description
+     "This package provides convenience functions for advanced linear algebra
+with tensors and computation with datasets of tensors on a higher level
+abstraction.  It includes Einstein and Riemann summing conventions, dragging,
+co- and contravariate indices, and parallel computations on sequences of
+tensors.")
+    (license license:gpl2+)))