[lesson2] Adding draft answers.

Author: Murilo Marinho

basic_lessons/lesson2_exercise_answers.ipynb

@@ -0,0 +1,155 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# L2 Exercise Answers\n",
+    "\n",
+    "*License: CC-BY-NC-SA 4.0*\n",
+    "\n",
+    "### I found an issue\n",
+    "Thank you! Please report it at https://github.com/MarinhoLab/OpenExecutableBooksRobotics/issues\n",
+    "\n",
+    "### Latex Macros"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {
+    "vscode": {
+     "languageId": "latex"
+    }
+   },
+   "source": [
+    "$\\providecommand{\\myvec}[1]{{\\mathbf{\\boldsymbol{{#1}}}}}$\n",
+    "$\\providecommand{\\mymatrix}[1]{{\\mathbf{\\boldsymbol{{#1}}}}}$"
+   ]
+  },
+  {
+   "cell_type": "raw",
+   "metadata": {
+    "vscode": {
+     "languageId": "raw"
+    }
+   },
+   "source": [
+    "\\providecommand{\\myvec}[1]{{\\mathbf{\\boldsymbol{{#1}}}}}\n",
+    "\\providecommand{\\mymatrix}[1]{{\\mathbf{\\boldsymbol{{#1}}}}}"
+   ]
+  },
+  {
+   "metadata": {},
+   "cell_type": "markdown",
+   "source": "# Valid imports"
+  },
+  {
+   "metadata": {},
+   "cell_type": "code",
+   "source": [
+    "from math import pi, sin, cos\n",
+    "import numpy as np"
+   ],
+   "outputs": [],
+   "execution_count": null
+  },
+  {
+   "metadata": {},
+   "cell_type": "markdown",
+   "source": [
+    "# Exercises\n",
+    "\n",
+    "## Exercise a"
+   ]
+  },
+  {
+   "metadata": {},
+   "cell_type": "code",
+   "source": [
+    "θ_a = pi/4.0\n",
+    "\n",
+    "R_a =  np.array([[cos(θ_a),-sin(θ_a)],\n",
+    "                 [sin(θ_a), cos(θ_a)]])\n",
+    "\n",
+    "# Printing the result is NOT a mandatory part of the answer.\n",
+    "print(f'R_a = {R_a}')"
+   ],
+   "outputs": [],
+   "execution_count": null
+  },
+  {
+   "metadata": {},
+   "cell_type": "markdown",
+   "source": "## Exercise b"
+  },
+  {
+   "metadata": {},
+   "cell_type": "code",
+   "source": [
+    "θ_b1 = pi/12.0\n",
+    "θ_b2 = -pi/2.0\n",
+    "\n",
+    "R_b1 =  np.array([[cos(θ_b1),-sin(θ_b1)],\n",
+    "                  [sin(θ_b1), cos(θ_b1)]])\n",
+    "\n",
+    "R_b2 =  np.array([[cos(θ_b2),-sin(θ_b2)],\n",
+    "                  [sin(θ_b2), cos(θ_b2)]])\n",
+    "\n",
+    "R_b = R_b1 @ R_b2\n",
+    "\n",
+    "print(f'R_b = {R_b}')"
+   ],
+   "outputs": [],
+   "execution_count": null
+  },
+  {
+   "metadata": {},
+   "cell_type": "markdown",
+   "source": "## Exercise c"
+  },
+  {
+   "metadata": {},
+   "cell_type": "code",
+   "source": [
+    "θ_c = pi/3.0 # As given in the exercise\n",
+    "x_c = 2.0 # As given in the exercise\n",
+    "y_c = 5.0 # As given in the exercise\n",
+    "\n",
+    "H_c1 = np.array([[cos(θ_c),-sin(θ_c), 0],\n",
+    "                 [sin(θ_c), cos(θ_c), 0],\n",
+    "                 [0,        0,        1]])\n",
+    "\n",
+    "H_c2 = np.array([[1,0,x_c],\n",
+    "                 [0,1,y_c],\n",
+    "                 [0,0,1]])\n",
+    "\n",
+    "H_c = H_c1 @ H_c2\n",
+    "\n",
+    "print(f'H_c = {H_c}')"
+   ],
+   "outputs": [],
+   "execution_count": null
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": ".venv",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.12.9"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}

basic_lessons/lesson2_tutorial.ipynb

@@ -608,7 +608,7 @@
    "source": [
     "θ_c = pi/3.0 # As given in the exercise\n",
     "x_c = 2.0 # As given in the exercise\n",
-    "y_c = 4.0 # As given in the exercise\n",
+    "y_c = 5.0 # As given in the exercise\n",
     "\n",
     "H_c = None # Replace None with your solution to this exercise."
    ],

myst.yml

@@ -40,6 +40,7 @@ project:
         - file: basic_lessons/lesson4_tutorial.ipynb
         - file: basic_lessons/lesson5_tutorial.ipynb
         - file: basic_lessons/lesson1_exercise_answers.ipynb
+        - file: basic_lessons/lesson2_exercise_answers.ipynb
     - title: "[Advanced] DQ Robotics"
       children:
         - file: dqrobotics/README.md