diff --git a/doc/pub/week39/html/week39-reveal.html b/doc/pub/week39/html/week39-reveal.html
index ca38d7215..010e2fc42 100644
--- a/doc/pub/week39/html/week39-reveal.html
+++ b/doc/pub/week39/html/week39-reveal.html
@@ -1316,7 +1316,8 @@ desirable properties such as:
     <div class="inner_cell">
       <div class="input_area">
         <div class="highlight" style="background: #eeeedd">
-  <pre style="font-size: 80%; line-height: 125%;">x = <span style="color: #B452CD">2</span>*np.random.rand(m,<span style="color: #B452CD">1</span>)
+  <pre style="font-size: 80%; line-height: 125%;">m = <span style="color: #B452CD">100</span>
+x = <span style="color: #B452CD">2</span>*np.random.rand(m,<span style="color: #B452CD">1</span>)
 y = <span style="color: #B452CD">4</span>+<span style="color: #B452CD">3</span>*x+np.random.randn(m,<span style="color: #B452CD">1</span>)
 </pre>
 </div>
diff --git a/doc/pub/week39/html/week39-solarized.html b/doc/pub/week39/html/week39-solarized.html
index 4d70cff9a..598fa5f80 100644
--- a/doc/pub/week39/html/week39-solarized.html
+++ b/doc/pub/week39/html/week39-solarized.html
@@ -1338,7 +1338,8 @@ desirable properties such as:
     <div class="inner_cell">
       <div class="input_area">
         <div class="highlight" style="background: #eeeedd">
-  <pre style="line-height: 125%;">x = <span style="color: #B452CD">2</span>*np.random.rand(m,<span style="color: #B452CD">1</span>)
+  <pre style="line-height: 125%;">m = <span style="color: #B452CD">100</span>
+x = <span style="color: #B452CD">2</span>*np.random.rand(m,<span style="color: #B452CD">1</span>)
 y = <span style="color: #B452CD">4</span>+<span style="color: #B452CD">3</span>*x+np.random.randn(m,<span style="color: #B452CD">1</span>)
 </pre>
 </div>
diff --git a/doc/pub/week39/html/week39.html b/doc/pub/week39/html/week39.html
index a7d3b6548..091eb2bc2 100644
--- a/doc/pub/week39/html/week39.html
+++ b/doc/pub/week39/html/week39.html
@@ -1415,7 +1415,8 @@ desirable properties such as:
     <div class="inner_cell">
       <div class="input_area">
         <div class="highlight" style="background: #f8f8f8">
-  <pre style="line-height: 125%;">x <span style="color: #666666">=</span> <span style="color: #666666">2*</span>np<span style="color: #666666">.</span>random<span style="color: #666666">.</span>rand(m,<span style="color: #666666">1</span>)
+  <pre style="line-height: 125%;">m <span style="color: #666666">=</span> <span style="color: #666666">100</span>
+x <span style="color: #666666">=</span> <span style="color: #666666">2*</span>np<span style="color: #666666">.</span>random<span style="color: #666666">.</span>rand(m,<span style="color: #666666">1</span>)
 y <span style="color: #666666">=</span> <span style="color: #666666">4+3*</span>x<span style="color: #666666">+</span>np<span style="color: #666666">.</span>random<span style="color: #666666">.</span>randn(m,<span style="color: #666666">1</span>)
 </pre>
 </div>
diff --git a/doc/pub/week39/ipynb/ipynb-week39-src.tar.gz b/doc/pub/week39/ipynb/ipynb-week39-src.tar.gz
index 9c04348bd..b6a9d3e55 100644
Binary files a/doc/pub/week39/ipynb/ipynb-week39-src.tar.gz and b/doc/pub/week39/ipynb/ipynb-week39-src.tar.gz differ
diff --git a/doc/pub/week39/ipynb/week39.ipynb b/doc/pub/week39/ipynb/week39.ipynb
index 67fc84a98..f2c1db99e 100644
--- a/doc/pub/week39/ipynb/week39.ipynb
+++ b/doc/pub/week39/ipynb/week39.ipynb
@@ -2,7 +2,7 @@
  "cells": [
   {
    "cell_type": "markdown",
-   "id": "c5ed1290",
+   "id": "7912fe42",
    "metadata": {
     "editable": true
    },
@@ -14,7 +14,7 @@
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   {
    "cell_type": "markdown",
-   "id": "3bbe62df",
+   "id": "d89866b9",
    "metadata": {
     "editable": true
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@@ -27,7 +27,7 @@
   },
   {
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-   "id": "6954aa21",
+   "id": "25dc772e",
    "metadata": {
     "editable": true
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@@ -37,7 +37,7 @@
   },
   {
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-   "id": "01c27e5f",
+   "id": "6fd1ad08",
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     "editable": true
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@@ -67,7 +67,7 @@
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   {
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+   "id": "c29de19e",
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@@ -94,7 +94,7 @@
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-   "id": "429cd901",
+   "id": "8c2fb525",
    "metadata": {
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@@ -115,7 +115,7 @@
   },
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-   "id": "df5685f9",
+   "id": "8ab048dc",
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@@ -132,7 +132,7 @@
   },
   {
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-   "id": "6c2039ef",
+   "id": "b6eee252",
    "metadata": {
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@@ -147,7 +147,7 @@
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-   "id": "044383ac",
+   "id": "6e93473a",
    "metadata": {
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@@ -157,7 +157,7 @@
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-   "id": "87926d76",
+   "id": "fe8726d4",
    "metadata": {
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@@ -173,7 +173,7 @@
   },
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-   "id": "1630039f",
+   "id": "2c8f7626",
    "metadata": {
     "editable": true
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@@ -185,7 +185,7 @@
   },
   {
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-   "id": "fce41128",
+   "id": "b9ee39d0",
    "metadata": {
     "editable": true
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@@ -196,7 +196,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "db3f46ef",
+   "id": "f6b25f06",
    "metadata": {
     "editable": true
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@@ -208,7 +208,7 @@
   },
   {
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+   "id": "6946d9b6",
    "metadata": {
     "editable": true
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@@ -218,7 +218,7 @@
   },
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-   "id": "3cb8e68c",
+   "id": "0eabcbc7",
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@@ -232,7 +232,7 @@
   },
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-   "id": "b417cfde",
+   "id": "1a7d92df",
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@@ -244,7 +244,7 @@
   },
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-   "id": "da2701fa",
+   "id": "5c0e1a36",
    "metadata": {
     "editable": true
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@@ -254,7 +254,7 @@
   },
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    "cell_type": "markdown",
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+   "id": "ebeb4e8d",
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@@ -266,7 +266,7 @@
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-   "id": "e9a6b151",
+   "id": "7052b120",
    "metadata": {
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@@ -278,7 +278,7 @@
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-   "id": "1d27234c",
+   "id": "576fea64",
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@@ -298,7 +298,7 @@
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-   "id": "b8489211",
+   "id": "d4cabbcf",
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     "editable": true
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@@ -314,7 +314,7 @@
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-   "id": "a6409d18",
+   "id": "c0594da7",
    "metadata": {
     "editable": true
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@@ -330,7 +330,7 @@
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-   "id": "4c79a0f3",
+   "id": "c7dfd5fe",
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@@ -341,7 +341,7 @@
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-   "id": "9bb173f4",
+   "id": "18a94243",
    "metadata": {
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@@ -353,7 +353,7 @@
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+   "id": "921d9964",
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@@ -363,7 +363,7 @@
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-   "id": "3fc079ac",
+   "id": "9ac3244b",
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@@ -375,7 +375,7 @@
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+   "id": "1be7b828",
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@@ -385,7 +385,7 @@
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+   "id": "aea6c852",
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@@ -397,7 +397,7 @@
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-   "id": "b050a2e8",
+   "id": "b9591305",
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@@ -419,7 +419,7 @@
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-   "id": "a8c7b5fc",
+   "id": "25d1dc06",
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@@ -432,7 +432,7 @@
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-   "id": "2329b48a",
+   "id": "612655fe",
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@@ -445,7 +445,7 @@
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   {
    "cell_type": "markdown",
-   "id": "089d0cf0",
+   "id": "a466321b",
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@@ -455,7 +455,7 @@
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-   "id": "63bd31f8",
+   "id": "2f4a85a5",
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@@ -473,7 +473,7 @@
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-   "id": "e2698e05",
+   "id": "a8cfbf90",
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@@ -483,7 +483,7 @@
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-   "id": "1b9f3d5a",
+   "id": "59e5128d",
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@@ -498,7 +498,7 @@
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-   "id": "15b9284f",
+   "id": "b5e63baa",
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@@ -508,7 +508,7 @@
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   {
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-   "id": "e5c200e0",
+   "id": "63010746",
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@@ -522,7 +522,7 @@
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-   "id": "673b4125",
+   "id": "3690a0e8",
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@@ -532,7 +532,7 @@
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-   "id": "906f1ebe",
+   "id": "8a560029",
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@@ -546,7 +546,7 @@
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+   "id": "c7de1d6e",
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@@ -561,7 +561,7 @@
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+   "id": "dc49339e",
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@@ -578,7 +578,7 @@
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@@ -590,7 +590,7 @@
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@@ -604,7 +604,7 @@
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@@ -619,7 +619,7 @@
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@@ -631,7 +631,7 @@
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@@ -642,7 +642,7 @@
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@@ -670,7 +670,7 @@
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@@ -692,7 +692,7 @@
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@@ -714,7 +714,7 @@
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@@ -735,7 +735,7 @@
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@@ -774,7 +774,7 @@
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@@ -802,7 +802,7 @@
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@@ -832,7 +832,7 @@
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@@ -852,7 +852,7 @@
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@@ -864,7 +864,7 @@
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@@ -874,7 +874,7 @@
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@@ -886,7 +886,7 @@
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@@ -898,7 +898,7 @@
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@@ -910,7 +910,7 @@
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@@ -922,7 +922,7 @@
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@@ -933,7 +933,7 @@
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@@ -946,7 +946,7 @@
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@@ -958,7 +958,7 @@
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@@ -968,7 +968,7 @@
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@@ -980,7 +980,7 @@
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@@ -990,7 +990,7 @@
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@@ -1001,7 +1001,7 @@
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@@ -1013,7 +1013,7 @@
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@@ -1025,7 +1025,7 @@
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@@ -1037,7 +1037,7 @@
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@@ -1048,7 +1048,7 @@
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@@ -1059,7 +1059,7 @@
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@@ -1071,7 +1071,7 @@
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@@ -1081,7 +1081,7 @@
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@@ -1093,7 +1093,7 @@
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@@ -1103,7 +1103,7 @@
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@@ -1115,7 +1115,7 @@
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@@ -1125,7 +1125,7 @@
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@@ -1137,7 +1137,7 @@
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@@ -1147,7 +1147,7 @@
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@@ -1159,7 +1159,7 @@
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@@ -1170,7 +1170,7 @@
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-   "id": "4f7bd984",
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@@ -1203,7 +1203,7 @@
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@@ -1214,7 +1214,7 @@
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-   "id": "8d3a4e82",
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@@ -1228,7 +1228,7 @@
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    "cell_type": "markdown",
-   "id": "64f06458",
+   "id": "523b0b6c",
    "metadata": {
     "editable": true
    },
@@ -1239,7 +1239,7 @@
   {
    "cell_type": "code",
    "execution_count": 3,
-   "id": "d7cab0fb",
+   "id": "baa7ec74",
    "metadata": {
     "collapsed": false,
     "editable": true
@@ -1252,7 +1252,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "c7484c17",
+   "id": "3a0d349b",
    "metadata": {
     "editable": true
    },
@@ -1263,7 +1263,7 @@
   {
    "cell_type": "code",
    "execution_count": 4,
-   "id": "2796af53",
+   "id": "00fbd4cc",
    "metadata": {
     "collapsed": false,
     "editable": true
@@ -1281,7 +1281,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "420291fd",
+   "id": "87aa5b1d",
    "metadata": {
     "editable": true
    },
@@ -1292,7 +1292,7 @@
   {
    "cell_type": "code",
    "execution_count": 5,
-   "id": "403929e9",
+   "id": "349148a7",
    "metadata": {
     "collapsed": false,
     "editable": true
@@ -1307,7 +1307,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "afdf78ca",
+   "id": "f7dd1962",
    "metadata": {
     "editable": true
    },
@@ -1317,7 +1317,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "4dfed98d",
+   "id": "56baae1e",
    "metadata": {
     "editable": true
    },
@@ -1331,7 +1331,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "d7da9fb8",
+   "id": "63dbf74b",
    "metadata": {
     "editable": true
    },
@@ -1343,7 +1343,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "2a9f120f",
+   "id": "430ff468",
    "metadata": {
     "editable": true
    },
@@ -1354,7 +1354,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "eedd81cd",
+   "id": "f08308f1",
    "metadata": {
     "editable": true
    },
@@ -1366,7 +1366,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3c651cfb",
+   "id": "6b846c95",
    "metadata": {
     "editable": true
    },
@@ -1377,7 +1377,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "e4895be8",
+   "id": "ae7f2d88",
    "metadata": {
     "editable": true
    },
@@ -1388,7 +1388,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "b7964d51",
+   "id": "1ed5e84c",
    "metadata": {
     "editable": true
    },
@@ -1400,7 +1400,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "d4878662",
+   "id": "889d1044",
    "metadata": {
     "editable": true
    },
@@ -1410,7 +1410,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "f12bf908",
+   "id": "ffc2c7ea",
    "metadata": {
     "editable": true
    },
@@ -1422,7 +1422,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "fd6a3335",
+   "id": "7042b1e9",
    "metadata": {
     "editable": true
    },
@@ -1434,7 +1434,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "c8572962",
+   "id": "e2a4c2da",
    "metadata": {
     "editable": true
    },
@@ -1446,7 +1446,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "13c283fd",
+   "id": "7c1ddd57",
    "metadata": {
     "editable": true
    },
@@ -1458,7 +1458,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "70dd0b10",
+   "id": "5054899b",
    "metadata": {
     "editable": true
    },
@@ -1469,7 +1469,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "b1194b8f",
+   "id": "5e884aa2",
    "metadata": {
     "editable": true
    },
@@ -1481,7 +1481,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "c6bf1f63",
+   "id": "ad8f85a3",
    "metadata": {
     "editable": true
    },
@@ -1491,7 +1491,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "512a74ea",
+   "id": "bf43f551",
    "metadata": {
     "editable": true
    },
@@ -1503,7 +1503,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "dc2956ee",
+   "id": "7a230f38",
    "metadata": {
     "editable": true
    },
@@ -1513,7 +1513,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "acde82a3",
+   "id": "94353cf4",
    "metadata": {
     "editable": true
    },
@@ -1525,7 +1525,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "35cf7ea4",
+   "id": "f75481db",
    "metadata": {
     "editable": true
    },
@@ -1545,7 +1545,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3dc6d91b",
+   "id": "56c3ee4a",
    "metadata": {
     "editable": true
    },
@@ -1557,7 +1557,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "b3b8eb99",
+   "id": "50ae8876",
    "metadata": {
     "editable": true
    },
@@ -1567,7 +1567,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "71d0cb5e",
+   "id": "a027ff77",
    "metadata": {
     "editable": true
    },
@@ -1579,7 +1579,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "db038148",
+   "id": "d646e340",
    "metadata": {
     "editable": true
    },
@@ -1589,7 +1589,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3377a0ef",
+   "id": "45bc5219",
    "metadata": {
     "editable": true
    },
@@ -1600,7 +1600,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "83350430",
+   "id": "bd6ffac4",
    "metadata": {
     "editable": true
    },
@@ -1612,7 +1612,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "af0a956c",
+   "id": "0a79d72c",
    "metadata": {
     "editable": true
    },
@@ -1624,7 +1624,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3c68a436",
+   "id": "9aee13e3",
    "metadata": {
     "editable": true
    },
@@ -1636,7 +1636,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "42938d76",
+   "id": "c35fa435",
    "metadata": {
     "editable": true
    },
@@ -1649,7 +1649,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "03e9d512",
+   "id": "8220bc37",
    "metadata": {
     "editable": true
    },
@@ -1660,7 +1660,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "9e0138cf",
+   "id": "21cbe0ab",
    "metadata": {
     "editable": true
    },
@@ -1672,7 +1672,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "6a873522",
+   "id": "f27fa615",
    "metadata": {
     "editable": true
    },
@@ -1688,7 +1688,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "935f1675",
+   "id": "0ea0d032",
    "metadata": {
     "editable": true
    },
@@ -1700,7 +1700,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "4b68d7da",
+   "id": "de47970d",
    "metadata": {
     "editable": true
    },
@@ -1711,7 +1711,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "b23796b3",
+   "id": "18d47ad2",
    "metadata": {
     "editable": true
    },
@@ -1723,7 +1723,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "081316b9",
+   "id": "99aca631",
    "metadata": {
     "editable": true
    },
@@ -1733,7 +1733,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "c2d5c344",
+   "id": "078b4a37",
    "metadata": {
     "editable": true
    },
@@ -1745,7 +1745,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "f6d65712",
+   "id": "040f74f6",
    "metadata": {
     "editable": true
    },
@@ -1755,7 +1755,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "b9756cc6",
+   "id": "abd29b5f",
    "metadata": {
     "editable": true
    },
@@ -1767,7 +1767,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "44242f94",
+   "id": "a1ad457f",
    "metadata": {
     "editable": true
    },
@@ -1777,7 +1777,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "4b82985c",
+   "id": "9bcaf2f7",
    "metadata": {
     "editable": true
    },
@@ -1789,7 +1789,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "387eb18c",
+   "id": "64026f5c",
    "metadata": {
     "editable": true
    },
@@ -1813,20 +1813,21 @@
   {
    "cell_type": "code",
    "execution_count": 6,
-   "id": "2aac8163",
+   "id": "106190b3",
    "metadata": {
     "collapsed": false,
     "editable": true
    },
    "outputs": [],
    "source": [
+    "m = 100\n",
     "x = 2*np.random.rand(m,1)\n",
     "y = 4+3*x+np.random.randn(m,1)"
    ]
   },
   {
    "cell_type": "markdown",
-   "id": "955c8686",
+   "id": "66e25471",
    "metadata": {
     "editable": true
    },
@@ -1837,7 +1838,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "49270547",
+   "id": "c044cf2d",
    "metadata": {
     "editable": true
    },
@@ -1849,7 +1850,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5350755c",
+   "id": "08753525",
    "metadata": {
     "editable": true
    },
@@ -1859,7 +1860,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "562c572f",
+   "id": "73642395",
    "metadata": {
     "editable": true
    },
@@ -1871,7 +1872,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "873d5184",
+   "id": "8add0083",
    "metadata": {
     "editable": true
    },
@@ -1885,7 +1886,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "5ebc3c03",
+   "id": "ad12a96b",
    "metadata": {
     "editable": true
    },
@@ -1901,7 +1902,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1b7a6157",
+   "id": "c559043e",
    "metadata": {
     "editable": true
    },
@@ -1911,7 +1912,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "7b4a7a6c",
+   "id": "905a151e",
    "metadata": {
     "editable": true
    },
@@ -1923,7 +1924,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "e4becced",
+   "id": "cd4ebc9c",
    "metadata": {
     "editable": true
    },
@@ -1933,7 +1934,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "f8919ae7",
+   "id": "bb10e963",
    "metadata": {
     "editable": true
    },
@@ -1945,7 +1946,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "66e2e249",
+   "id": "dd7aaffc",
    "metadata": {
     "editable": true
    },
@@ -1959,7 +1960,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "baf18cd1",
+   "id": "f352990f",
    "metadata": {
     "editable": true
    },
@@ -1969,7 +1970,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "3d433c9a",
+   "id": "de0368ae",
    "metadata": {
     "editable": true
    },
@@ -1980,7 +1981,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "d0cf5d0a",
+   "id": "9acd9f97",
    "metadata": {
     "editable": true
    },
@@ -1995,7 +1996,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "a7214e13",
+   "id": "dba1f383",
    "metadata": {
     "editable": true
    },
@@ -2005,7 +2006,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "a23f208c",
+   "id": "8d97c1f3",
    "metadata": {
     "editable": true
    },
@@ -2017,7 +2018,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1851b1ec",
+   "id": "b87ee47d",
    "metadata": {
     "editable": true
    },
@@ -2029,7 +2030,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "11b59aa6",
+   "id": "21822b7c",
    "metadata": {
     "editable": true
    },
@@ -2044,7 +2045,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "b78125b4",
+   "id": "4dbf0844",
    "metadata": {
     "editable": true
    },
@@ -2057,7 +2058,7 @@
   {
    "cell_type": "code",
    "execution_count": 7,
-   "id": "fe6d8a3f",
+   "id": "1483839a",
    "metadata": {
     "collapsed": false,
     "editable": true
@@ -2114,7 +2115,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "992a18e6",
+   "id": "d82b8fba",
    "metadata": {
     "editable": true
    },
@@ -2125,7 +2126,7 @@
   {
    "cell_type": "code",
    "execution_count": 8,
-   "id": "b26e2456",
+   "id": "35dd2d56",
    "metadata": {
     "collapsed": false,
     "editable": true
@@ -2152,7 +2153,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "82511df2",
+   "id": "cc2b2b07",
    "metadata": {
     "editable": true
    },
@@ -2164,7 +2165,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "cb6456a6",
+   "id": "68ef0a9e",
    "metadata": {
     "editable": true
    },
@@ -2176,7 +2177,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "bb65410f",
+   "id": "450edd74",
    "metadata": {
     "editable": true
    },
@@ -2186,7 +2187,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "df0bc755",
+   "id": "6795c942",
    "metadata": {
     "editable": true
    },
@@ -2200,7 +2201,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "85b828e9",
+   "id": "cf47f53c",
    "metadata": {
     "editable": true
    },
@@ -2210,7 +2211,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "16307de8",
+   "id": "146c6225",
    "metadata": {
     "editable": true
    },
@@ -2222,7 +2223,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "ce41a9ed",
+   "id": "a51b016e",
    "metadata": {
     "editable": true
    },
@@ -2233,7 +2234,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "e43da986",
+   "id": "77bd1312",
    "metadata": {
     "editable": true
    },
@@ -2248,7 +2249,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "f24b51f7",
+   "id": "383bb7fb",
    "metadata": {
     "editable": true
    },
@@ -2262,7 +2263,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "84409546",
+   "id": "9981b4f5",
    "metadata": {
     "editable": true
    },
@@ -2273,7 +2274,7 @@
   {
    "cell_type": "code",
    "execution_count": 9,
-   "id": "25d78bca",
+   "id": "ef54dba4",
    "metadata": {
     "collapsed": false,
     "editable": true
@@ -2334,7 +2335,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1ed8347f",
+   "id": "592b33e9",
    "metadata": {
     "editable": true
    },
@@ -2356,7 +2357,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "75538b49",
+   "id": "00fa51d5",
    "metadata": {
     "editable": true
    },
@@ -2369,7 +2370,7 @@
   {
    "cell_type": "code",
    "execution_count": 10,
-   "id": "5e06d4eb",
+   "id": "942fa47b",
    "metadata": {
     "collapsed": false,
     "editable": true
@@ -2435,7 +2436,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "4ddcb1bf",
+   "id": "b185af42",
    "metadata": {
     "editable": true
    },
@@ -2446,7 +2447,7 @@
   {
    "cell_type": "code",
    "execution_count": 11,
-   "id": "ba4db7cc",
+   "id": "a4b80331",
    "metadata": {
     "collapsed": false,
     "editable": true
@@ -2520,7 +2521,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "86a47fd3",
+   "id": "a5259922",
    "metadata": {
     "editable": true
    },
@@ -2532,7 +2533,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "89d1b61f",
+   "id": "49ecbea3",
    "metadata": {
     "editable": true
    },
@@ -2553,7 +2554,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "a20b8dae",
+   "id": "0cb18a81",
    "metadata": {
     "editable": true
    },
@@ -2585,7 +2586,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "a7676c9f",
+   "id": "5e9c9d01",
    "metadata": {
     "editable": true
    },
@@ -2602,7 +2603,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "02e7490a",
+   "id": "1cd6de84",
    "metadata": {
     "editable": true
    },
@@ -2615,7 +2616,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "67dcc1a6",
+   "id": "4b723b6c",
    "metadata": {
     "editable": true
    },
@@ -2628,7 +2629,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "1aa89ba5",
+   "id": "e6eb4091",
    "metadata": {
     "editable": true
    },
@@ -2641,7 +2642,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "4be2f4af",
+   "id": "f2ff38c6",
    "metadata": {
     "editable": true
    },
@@ -2655,7 +2656,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "7e9e30f7",
+   "id": "054d9a61",
    "metadata": {
     "editable": true
    },
@@ -2677,7 +2678,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "8254ca90",
+   "id": "adf4bbf4",
    "metadata": {
     "editable": true
    },
@@ -2692,7 +2693,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "73357038",
+   "id": "2790a7f2",
    "metadata": {
     "editable": true
    },
@@ -2704,7 +2705,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "752c0927",
+   "id": "a36b3210",
    "metadata": {
     "editable": true
    },
@@ -2717,7 +2718,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "fd66f846",
+   "id": "046b2916",
    "metadata": {
     "editable": true
    },
@@ -2731,7 +2732,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "a4dde872",
+   "id": "5e55b6ee",
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@@ -2742,7 +2743,7 @@
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@@ -2767,7 +2768,7 @@
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@@ -2783,7 +2784,7 @@
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@@ -2804,7 +2805,7 @@
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@@ -2824,7 +2825,7 @@
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@@ -2843,7 +2844,7 @@
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@@ -2878,7 +2879,7 @@
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@@ -2891,7 +2892,7 @@
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@@ -2968,7 +2969,7 @@
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@@ -2983,7 +2984,7 @@
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@@ -2998,7 +2999,7 @@
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@@ -3010,7 +3011,7 @@
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@@ -3028,7 +3029,7 @@
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@@ -3047,7 +3048,7 @@
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@@ -3059,7 +3060,7 @@
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@@ -3069,7 +3070,7 @@
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@@ -3085,7 +3086,7 @@
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@@ -3097,7 +3098,7 @@
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@@ -3107,7 +3108,7 @@
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@@ -3119,7 +3120,7 @@
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@@ -3129,7 +3130,7 @@
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@@ -3141,7 +3142,7 @@
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@@ -3157,7 +3158,7 @@
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@@ -3169,7 +3170,7 @@
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@@ -3202,7 +3203,7 @@
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@@ -3214,7 +3215,7 @@
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@@ -3232,7 +3233,7 @@
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@@ -3242,7 +3243,7 @@
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@@ -3273,7 +3274,7 @@
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@@ -3288,7 +3289,7 @@
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@@ -3306,7 +3307,7 @@
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@@ -3318,7 +3319,7 @@
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@@ -3330,7 +3331,7 @@
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@@ -3348,7 +3349,7 @@
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@@ -3377,7 +3378,7 @@
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@@ -3395,7 +3396,7 @@
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@@ -3407,7 +3408,7 @@
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@@ -3419,7 +3420,7 @@
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@@ -3431,7 +3432,7 @@
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@@ -3443,7 +3444,7 @@
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@@ -3455,7 +3456,7 @@
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@@ -3472,7 +3473,7 @@
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@@ -3491,7 +3492,7 @@
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@@ -3503,7 +3504,7 @@
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@@ -3517,7 +3518,7 @@
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@@ -3537,7 +3538,7 @@
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@@ -3575,7 +3576,7 @@
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@@ -3587,7 +3588,7 @@
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@@ -3597,7 +3598,7 @@
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@@ -3609,7 +3610,7 @@
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@@ -3620,7 +3621,7 @@
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@@ -3665,7 +3666,7 @@
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@@ -3682,7 +3683,7 @@
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@@ -3710,7 +3711,7 @@
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@@ -3725,7 +3726,7 @@
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@@ -3769,7 +3770,7 @@
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@@ -3779,7 +3780,7 @@
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@@ -3790,7 +3791,7 @@
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@@ -3818,7 +3819,7 @@
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@@ -3833,7 +3834,7 @@
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@@ -3844,7 +3845,7 @@
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@@ -3872,7 +3873,7 @@
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@@ -3883,7 +3884,7 @@
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@@ -3908,7 +3909,7 @@
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@@ -3919,7 +3920,7 @@
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@@ -3955,7 +3956,7 @@
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@@ -3975,7 +3976,7 @@
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@@ -3986,7 +3987,7 @@
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@@ -4024,7 +4025,7 @@
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@@ -4034,7 +4035,7 @@
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@@ -4048,7 +4049,7 @@
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@@ -4070,7 +4071,7 @@
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@@ -4080,7 +4081,7 @@
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@@ -4091,7 +4092,7 @@
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@@ -4113,7 +4114,7 @@
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@@ -4126,7 +4127,7 @@
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@@ -4151,7 +4152,7 @@
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@@ -4163,7 +4164,7 @@
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@@ -4178,7 +4179,7 @@
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@@ -4193,7 +4194,7 @@
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@@ -4253,7 +4254,7 @@
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@@ -4264,7 +4265,7 @@
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@@ -4328,7 +4329,7 @@
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@@ -4339,7 +4340,7 @@
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@@ -4388,7 +4389,7 @@
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@@ -4400,7 +4401,7 @@
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@@ -4484,7 +4485,7 @@
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@@ -4495,7 +4496,7 @@
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@@ -4573,7 +4574,7 @@
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@@ -4584,7 +4585,7 @@
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@@ -4643,7 +4644,7 @@
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@@ -4653,7 +4654,7 @@
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@@ -4664,7 +4665,7 @@
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@@ -4729,7 +4730,7 @@
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@@ -4740,7 +4741,7 @@
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@@ -4810,7 +4811,7 @@
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@@ -4821,7 +4822,7 @@
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@@ -4865,7 +4866,7 @@
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@@ -4884,7 +4885,7 @@
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    "cell_type": "code",
    "execution_count": 37,
-   "id": "79c726a2",
+   "id": "0b125b34",
    "metadata": {
     "collapsed": false,
     "editable": true
diff --git a/doc/src/week39/week39.do.txt b/doc/src/week39/week39.do.txt
index a093c38b4..77b8c1328 100644
--- a/doc/src/week39/week39.do.txt
+++ b/doc/src/week39/week39.do.txt
@@ -815,6 +815,7 @@ o The cost function is convex which guarantees that gradient descent converges f
 We revisit an example similar to what we had in the first homework set. We had a function  of the type
 
 !bc pycod
+m = 100
 x = 2*np.random.rand(m,1)
 y = 4+3*x+np.random.randn(m,1)
 !ec