Tidy up math notation

Author: petercorke

symbolic/angvelxform_dot.ipynb

@@ -13,7 +13,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 20,
+   "execution_count": 2,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -41,14 +41,14 @@
     "\n",
     "\n",
     "$\n",
-    "\\mathbf{A} = I_{3 \\times 3} - \\frac{1}{2} [v]_\\times + [v]^2_\\times \\frac{1}{\\theta^2} \\left( 1 - \\frac{\\theta}{2} \\frac{\\sin \\theta}{1 - \\cos \\theta} \\right)\n",
+    "\\mathbf{A} = \\mathbf{1}_{3 \\times 3} - \\frac{1}{2} [v]_\\times + [v]^2_\\times \\frac{1}{\\theta^2} \\left( 1 - \\frac{\\theta}{2} \\frac{\\sin \\theta}{1 - \\cos \\theta} \\right)\n",
     "$\n",
     "where $\\theta = \\| \\varphi \\|$ and $v = \\hat{\\varphi}$\n",
     "\n",
     "We simplify the equation as\n",
     "\n",
     "$\n",
-    "\\mathbf{A} = I_{3 \\times 3} - \\frac{1}{2} [v]_\\times + [v]^2_\\times \\Theta\n",
+    "\\mathbf{A} = \\mathbf{1}_{3 \\times 3} - \\frac{1}{2} [v]_\\times + [v]^2_\\times \\Theta\n",
     "$\n",
     "\n",
     "where\n",
@@ -308,6 +308,26 @@
    "source": [
     "which is simply the dot product over the norm."
    ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "exp(A(t))*Derivative(A(t), t)\n"
+     ]
+    }
+   ],
+   "source": [
+    "A, t = symbols('A t', real=True)\n",
+    "A_t = Function(A)(t)\n",
+    "d = diff(exp(A_t), t)\n",
+    "print(d)"
+   ]
   }
  ],
  "metadata": {