Update ho-to-guides examples

Author: KybernetikJo

doc/source/guides/ab13dd_nb.ipynb

@@ -7,7 +7,17 @@
    "source": [
     "# ab13dd Example\n",
     "\n",
-    "Johannes Kaisinger, 26 July 2023"
+    "Johannes Kaisinger, 26 July 2023\n",
+    "\n",
+    "The `ab13dd` calculates the L-infinity norm of a state space system.\n",
+    "For a stable system it is equal to the H-infintiy norm."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Create data"
    ]
   },
   {
@@ -89,16 +99,16 @@
     "    \"\"\"naive implementation of bisection algorithm for H-infinity norm\n",
     "\n",
     "    Args:\n",
-    "        A (_type_): _description_\n",
-    "        B (_type_): _description_\n",
-    "        C (_type_): _description_\n",
-    "        D (_type_): _description_\n",
-    "        gam_l (_type_): _description_\n",
-    "        gam_h (_type_): _description_\n",
-    "        emin (_type_): _description_\n",
+    "        A (_type_): system matrix\n",
+    "        B (_type_): input matrix\n",
+    "        C (_type_): output matrix\n",
+    "        D (_type_): feedthrough matrix\n",
+    "        gam_l (_type_): low bound for norm\n",
+    "        gam_h (_type_): upper bound for norm\n",
+    "        emin (_type_): min difference between gam_l and gam_h\n",
     "\n",
     "    Returns:\n",
-    "        _type_: _description_\n",
+    "        float: norm\n",
     "    \"\"\"\n",
     "    gam_last_stable = None\n",
     "    while (gam_h - gam_l) > emin:\n",

doc/source/guides/index.rst

@@ -0,0 +1,12 @@
+:orphan:
+
+Examples
+========
+
+The following notebooks show some use cases for Slycot.
+
+.. toctree::
+   :maxdepth: 1
+
+   system_norms
+   sysid

doc/source/guides/sy10yd_nb.ipynb

@@ -0,0 +1,10 @@
+
+:orphan:
+
+System identification
+=====================
+
+.. toctree::
+   :maxdepth: 1
+
+   sy10yd_nb

doc/source/guides/sysid.rst

@@ -46,7 +46,7 @@ The Slycot library is organised by chapters. Each chapter can be identified by a
    :hidden:
    :caption: 🪄 How-to guides
 
-   /guides/system_norms
+   /guides/index
 
 .. toctree::
    :maxdepth: 2