(r-rcpp)ensmallen: new package (#38249)

* ensmallen: new package
  ensmallen is a high-quality C++ library for non-linear numerical optimization.
* r-rcppensmallen: new package

---------

Co-authored-by: wdconinc <wdconinc@users.noreply.github.com>

var/spack/repos/builtin/packages/ensmallen/package.py

@@ -0,0 +1,31 @@
+# Copyright 2013-2023 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack.package import *
+
+
+class Ensmallen(CMakePackage):
+    """ensmallen is a high-quality C++ library for non-linear numerical
+    optimization.
+
+    ensmallen provides many types of optimizers that can be used for
+    virtually any numerical optimization task. This includes gradient
+    descent techniques, gradient-free optimizers, and constrained
+    optimization. ensmallen also allows optional callbacks to customize
+    the optimization process."""
+
+    homepage = "https://ensmallen.org"
+    url = "https://github.com/mlpack/ensmallen/archive/refs/tags/2.19.1.tar.gz"
+
+    version("2.19.1", sha256="f36ad7f08b0688d2a8152e1c73dd437c56ed7a5af5facf65db6ffd977b275b2e")
+
+    variant("openmp", default=True, description="Use OpenMP for parallelization")
+
+    depends_on("cmake@3.3.2:")
+    depends_on("armadillo@9.800.0:")
+
+    def cmake_args(self):
+        args = [self.define_from_variant("USE_OPENMP", "openmp")]
+        return args

var/spack/repos/builtin/packages/r-rcppensmallen/package.py

@@ -0,0 +1,20 @@
+# Copyright 2013-2023 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack.package import *
+
+
+class RRcppensmallen(RPackage):
+    """Rcpp integration for the Ensmallen templated C++ mathematical    optimization library."""
+
+    cran = "RcppEnsmallen"
+
+    version(
+        "0.2.19.0.1", sha256="b4a9bde4dde309a52a47b56790389ecab14fe64066098d2a38b1b588ba3d8631"
+    )
+
+    depends_on("r@3.3.0:", type=("build", "run"))
+    depends_on("r-rcpp", type=("build", "run"))
+    depends_on("r-rcpparmadillo@0.9.800.0.0:", type=("build", "run"))