Improve example notebook

environment.yml

@@ -4,4 +4,6 @@ channels:
   - conda-forge
 dependencies:
   - xeus-cling=0.4.5
+  - xtensor=0.16.4
+  - xtensor-blas=0.11.1
   - notebook

notebooks/xcpp.ipynb

@@ -635,6 +635,117 @@
    "source": [
     "%timeit std::random_shuffle(to_shuffle.begin(), to_shuffle.end());"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "[![xtensor](images/xtensor.png)](https://github.com/QuantStack/xtensor/)\n",
+    "\n",
+    "- GitHub repository: https://github.com/QuantStack/xtensor/\n",
+    "- Online documentation: https://xtensor.readthedocs.io/\n",
+    "- NumPy to xtensor cheat sheet: http://xtensor.readthedocs.io/en/latest/numpy.html\n",
+    "\n",
+    "`xtensor` is a C++ library for manipulating N-D arrays with an API very similar to that of numpy."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#include <iostream>\n",
+    "\n",
+    "#include \"xtensor/xarray.hpp\"\n",
+    "#include \"xtensor/xio.hpp\"\n",
+    "#include \"xtensor/xview.hpp\"\n",
+    "\n",
+    "xt::xarray<double> arr1\n",
+    "  {{1.0, 2.0, 3.0},\n",
+    "   {2.0, 5.0, 7.0},\n",
+    "   {2.0, 5.0, 7.0}};\n",
+    "\n",
+    "xt::xarray<double> arr2\n",
+    "  {5.0, 6.0, 7.0};\n",
+    "\n",
+    "xt::view(arr1, 1) + arr2"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Together with the C++ Jupyter kernel, `xtensor` offers a similar experience as `NumPy` in the Python Jupyter kernel, including broadcasting and universal functions."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#include <iostream>\n",
+    "#include \"xtensor/xarray.hpp\"\n",
+    "#include \"xtensor/xio.hpp\""
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "xt::xarray<int> arr\n",
+    "  {1, 2, 3, 4, 5, 6, 7, 8, 9};\n",
+    "\n",
+    "arr.reshape({3, 3});\n",
+    "\n",
+    "std::cout << arr;"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#include \"xtensor-blas/xlinalg.hpp\""
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "xt::xtensor<double, 2> m = {{1.5, 0.5}, {0.7, 1.0}};\n",
+    "std::cout << \"Matrix rank: \" << std::endl << xt::linalg::matrix_rank(m) << std::endl;\n",
+    "std::cout << \"Matrix inverse: \" << std::endl << xt::linalg::inv(m) << std::endl;\n",
+    "std::cout << \"Eigen values: \" << std::endl << xt::linalg::eigvals(m) << std::endl;"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "xt::xarray<double> arg1 = xt::arange<double>(9);\n",
+    "xt::xarray<double> arg2 = xt::arange<double>(18);\n",
+    "\n",
+    "arg1.reshape({3, 3});\n",
+    "arg2.reshape({2, 3, 3});\n",
+    "\n",
+    "std::cout << xt::linalg::dot(arg1, arg2) << std::endl;"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
   }
  ],
  "metadata": {