From f5ff90cb80b434af2f78f6610a142123cbd6e4a8 Mon Sep 17 00:00:00 2001
From: Kees van Kempen <k.vankempen@student.science.ru.nl>
Date: Thu, 17 Feb 2022 12:58:07 +0100
Subject: [PATCH] 07: Add matrices to begin with

---
 Week 3/7 Linear Equation Systems.ipynb | 57 +++++++++++++++++++++-----
 1 file changed, 47 insertions(+), 10 deletions(-)

diff --git a/Week 3/7 Linear Equation Systems.ipynb b/Week 3/7 Linear Equation Systems.ipynb
index e58aa77..d622fe0 100644
--- a/Week 3/7 Linear Equation Systems.ipynb	
+++ b/Week 3/7 Linear Equation Systems.ipynb	
@@ -39,7 +39,7 @@
    "cell_type": "raw",
    "metadata": {},
    "source": [
-    "team_members = \"\""
+    "team_members = \"Koen Vendrig, Kees van Kempen\""
    ]
   },
   {
@@ -70,7 +70,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 7,
    "metadata": {
     "deletable": false,
     "nbgrader": {
@@ -85,12 +85,38 @@
      "task": false
     }
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "array([[ 1.75781401,  1.51265934, -2.74738978, -1.07039898,  0.8011521 ,\n",
+       "         1.4647544 ],\n",
+       "       [-2.71620167, -0.86457733,  0.10081129, -0.73161518, -2.78224414,\n",
+       "         0.41565052],\n",
+       "       [-0.67163289,  1.56932333,  2.48595706, -2.40628501,  0.71051658,\n",
+       "        -0.69975624],\n",
+       "       [ 1.58537064,  1.68053005,  2.06468208,  2.35512153, -0.66624755,\n",
+       "         2.62150694],\n",
+       "       [-3.14413521, -2.23161046,  1.14029891, -1.55518494,  2.72967878,\n",
+       "        -2.42673772],\n",
+       "       [-2.97430088, -2.15350692, -2.82033592,  2.92079141,  2.94935414,\n",
+       "        -0.35649436]])"
+      ]
+     },
+     "execution_count": 7,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
    "source": [
-    "# Import packages here ...\n",
+    "import numpy as np\n",
     "\n",
-    "# YOUR CODE HERE\n",
-    "raise NotImplementedError()"
+    "# We'll generate a random matrix, but for now we're unsure whether it results in a\n",
+    "# solvable system.\n",
+    "n = 6\n",
+    "A =  7*(np.random.rand(n,n) - .5)\n",
+    "b = 13*(np.random.rand(n)   - .5)\n",
+    "A"
    ]
   },
   {
@@ -118,7 +144,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 6,
    "metadata": {
     "deletable": false,
     "nbgrader": {
@@ -136,8 +162,7 @@
    "outputs": [],
    "source": [
     "def diff(a, b):\n",
-    "    # YOUR CODE HERE\n",
-    "    raise NotImplementedError()"
+    "    return np.max(a - b)"
    ]
   },
   {
@@ -312,6 +337,12 @@
    },
    "outputs": [],
    "source": [
+    "# Here, Koen, I made the matrix.\n",
+    "A = np.array([[ 10, - 1,   2,   0],\n",
+    "              [- 1,  11, - 1,   3],\n",
+    "              [  2, - 1,  10, - 1],\n",
+    "              [  0,   3, - 1,   8]])\n",
+    "b = np.array( [  6,  25, -11,  15])\n",
     "# Do your plotting here ...\n",
     "\n",
     "# YOUR CODE HERE\n",
@@ -583,6 +614,12 @@
    },
    "outputs": [],
    "source": [
+    "A = np.array([[  .2,   .1,   1.0,  1.0,    0.0],\n",
+    "              [  .1,  4.0, - 1.0,  1.0, -  1.0],\n",
+    "              [ 1.0, -1.0,  60.0,   .0,     .0],\n",
+    "              [ 1.0,  1.0,    .0,  8.0,    4.0],\n",
+    "              [  .0, -1.0, - 2.0,  4.0,  700.0]])\n",
+    "b = np.array( [ 1  ,  2  ,   3  ,  4  ,    5  ] )\n",
     "# YOUR CODE HERE\n",
     "raise NotImplementedError()"
    ]
@@ -647,7 +684,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3 (ipykernel)",
+   "display_name": "Python 3",
    "language": "python",
    "name": "python3"
   },