Updating notebooks

03_motion.ipynb

@@ -57,7 +57,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": 55,
    "metadata": {
     "tags": []
    },
@@ -69,7 +69,7 @@
     "IN_COLAB = 'google.colab' in sys.modules\n",
     "\n",
     "if IN_COLAB:\n",
-    "    !pip install astroquery astro-gala wget"
+    "    !pip install astroquery astro-gala"
    ]
   },
   {
@@ -87,7 +87,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": 56,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -113,7 +113,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 57,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -134,7 +134,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 3,
+   "execution_count": 58,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -154,7 +154,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 59,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -170,7 +170,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 60,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -186,7 +186,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 6,
+   "execution_count": 61,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -202,7 +202,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 62,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -218,7 +218,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
+   "execution_count": 63,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -237,7 +237,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 9,
+   "execution_count": 64,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -253,7 +253,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 10,
+   "execution_count": 65,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -281,7 +281,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 11,
+   "execution_count": 66,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -321,7 +321,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 12,
+   "execution_count": 67,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -364,7 +364,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 13,
+   "execution_count": 68,
    "metadata": {
     "tags": []
    },
@@ -393,7 +393,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 14,
+   "execution_count": 69,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -415,7 +415,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 15,
+   "execution_count": 70,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -445,7 +445,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 16,
+   "execution_count": 71,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -490,7 +490,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 17,
+   "execution_count": 72,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -514,7 +514,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 18,
+   "execution_count": 73,
    "metadata": {
     "scrolled": true
    },
@@ -546,7 +546,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 19,
+   "execution_count": 74,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -562,7 +562,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 20,
+   "execution_count": 75,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -588,7 +588,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 22,
+   "execution_count": 76,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -606,7 +606,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 23,
+   "execution_count": 77,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -622,7 +622,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 24,
+   "execution_count": 78,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -645,7 +645,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 25,
+   "execution_count": 79,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -663,7 +663,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 26,
+   "execution_count": 80,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -693,7 +693,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 27,
+   "execution_count": 81,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -715,7 +715,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 40,
+   "execution_count": 82,
    "metadata": {
     "tags": []
    },
@@ -753,7 +753,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 28,
+   "execution_count": 83,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -775,7 +775,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 29,
+   "execution_count": 84,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -817,7 +817,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 31,
+   "execution_count": 85,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -836,7 +836,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 32,
+   "execution_count": 86,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -856,7 +856,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 33,
+   "execution_count": 87,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -873,7 +873,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 34,
+   "execution_count": 88,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -898,7 +898,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 35,
+   "execution_count": 89,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -914,7 +914,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 36,
+   "execution_count": 90,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -934,7 +934,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 37,
+   "execution_count": 91,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -950,7 +950,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 53,
+   "execution_count": 92,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -975,7 +975,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 38,
+   "execution_count": 93,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1004,7 +1004,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 39,
+   "execution_count": 94,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1041,7 +1041,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 40,
+   "execution_count": 95,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1060,7 +1060,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 41,
+   "execution_count": 96,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1073,7 +1073,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 42,
+   "execution_count": 97,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1090,7 +1090,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 43,
+   "execution_count": 98,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1109,7 +1109,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 44,
+   "execution_count": 99,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1127,7 +1127,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 45,
+   "execution_count": 100,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1147,7 +1147,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 46,
+   "execution_count": 101,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1163,7 +1163,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 47,
+   "execution_count": 102,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1180,7 +1180,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 48,
+   "execution_count": 103,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1212,7 +1212,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 49,
+   "execution_count": 104,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1253,7 +1253,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 50,
+   "execution_count": 105,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1286,7 +1286,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 51,
+   "execution_count": 106,
    "metadata": {
     "tags": []
    },
@@ -1304,7 +1304,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 56,
+   "execution_count": 107,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1323,7 +1323,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 53,
+   "execution_count": 108,
    "metadata": {},
    "outputs": [],
    "source": [

04_select.ipynb

@@ -52,7 +52,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": 37,
    "metadata": {
     "tags": []
    },
@@ -64,7 +64,7 @@
     "IN_COLAB = 'google.colab' in sys.modules\n",
     "\n",
     "if IN_COLAB:\n",
-    "    !pip install astroquery astro-gala wget"
+    "    !pip install astroquery astro-gala"
    ]
   },
   {
@@ -73,12 +73,12 @@
    "source": [
     "## Reload the data\n",
     "\n",
-    "The following cells download the data from the previous lesson, if necessary, and load it into a Pandas `DataFrame`."
+    "You can [download the data from the previous lesson](https://github.com/AllenDowney/AstronomicalData/raw/main/data/gd1_data.hdf) or run the following cell, which downloads it if necessary."
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 38,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -95,9 +95,16 @@
     "         'data/gd1_data.hdf')"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Now we can reload `centerline_df` and `selected_df`."
+   ]
+  },
   {
    "cell_type": "code",
-   "execution_count": 3,
+   "execution_count": 39,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -135,7 +142,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 40,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -147,7 +154,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 41,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -160,7 +167,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 6,
+   "execution_count": 42,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -177,7 +184,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 43,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -214,7 +221,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
+   "execution_count": 44,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -236,7 +243,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 9,
+   "execution_count": 45,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -277,7 +284,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 10,
+   "execution_count": 46,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -303,7 +310,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 11,
+   "execution_count": 47,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -322,7 +329,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 12,
+   "execution_count": 48,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -338,7 +345,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 13,
+   "execution_count": 49,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -355,7 +362,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 14,
+   "execution_count": 50,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -373,7 +380,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 15,
+   "execution_count": 51,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -413,7 +420,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 16,
+   "execution_count": 52,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -442,7 +449,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 17,
+   "execution_count": 53,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -463,7 +470,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 18,
+   "execution_count": 54,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -480,7 +487,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 19,
+   "execution_count": 55,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -505,7 +512,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 20,
+   "execution_count": 56,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -518,7 +525,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 21,
+   "execution_count": 57,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -535,7 +542,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 22,
+   "execution_count": 58,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -551,7 +558,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 23,
+   "execution_count": 59,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -583,7 +590,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 24,
+   "execution_count": 60,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -602,7 +609,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 25,
+   "execution_count": 61,
    "metadata": {
     "scrolled": true
    },
@@ -623,7 +630,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 26,
+   "execution_count": 62,
    "metadata": {
     "tags": []
    },
@@ -643,7 +650,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 27,
+   "execution_count": 63,
    "metadata": {
     "tags": []
    },
@@ -661,7 +668,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 28,
+   "execution_count": 64,
    "metadata": {
     "scrolled": true
    },
@@ -682,7 +689,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 29,
+   "execution_count": 65,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -706,7 +713,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 30,
+   "execution_count": 66,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -723,7 +730,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 31,
+   "execution_count": 67,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -740,7 +747,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 32,
+   "execution_count": 68,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -759,7 +766,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 33,
+   "execution_count": 69,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -783,7 +790,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 34,
+   "execution_count": 70,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -825,7 +832,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 35,
+   "execution_count": 71,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -841,7 +848,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 36,
+   "execution_count": 72,
    "metadata": {},
    "outputs": [],
    "source": [

05_join.ipynb

@@ -56,7 +56,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": 28,
    "metadata": {
     "tags": []
    },
@@ -131,7 +131,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 29,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -142,7 +142,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 3,
+   "execution_count": 30,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -158,7 +158,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 31,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -189,7 +189,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 32,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -202,7 +202,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 6,
+   "execution_count": 33,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -211,7 +211,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 34,
    "metadata": {
     "scrolled": true
    },
@@ -232,7 +232,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
+   "execution_count": 35,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -241,7 +241,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 9,
+   "execution_count": 36,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -257,7 +257,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 10,
+   "execution_count": 37,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -284,7 +284,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 11,
+   "execution_count": 38,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -297,7 +297,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 12,
+   "execution_count": 39,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -306,7 +306,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 13,
+   "execution_count": 40,
    "metadata": {
     "scrolled": true
    },
@@ -350,7 +350,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 14,
+   "execution_count": 41,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -373,7 +373,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 15,
+   "execution_count": 42,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -384,7 +384,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 16,
+   "execution_count": 43,
    "metadata": {
     "scrolled": true
    },
@@ -404,7 +404,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 17,
+   "execution_count": 44,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -426,7 +426,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 18,
+   "execution_count": 45,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -445,7 +445,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 19,
+   "execution_count": 46,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -454,7 +454,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 20,
+   "execution_count": 47,
    "metadata": {
     "scrolled": true
    },
@@ -484,7 +484,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 21,
+   "execution_count": 48,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -516,7 +516,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 22,
+   "execution_count": 49,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -536,7 +536,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 23,
+   "execution_count": 50,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -545,7 +545,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 24,
+   "execution_count": 51,
    "metadata": {
     "scrolled": true
    },
@@ -583,7 +583,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 25,
+   "execution_count": 52,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -603,7 +603,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 29,
+   "execution_count": 53,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -628,7 +628,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 30,
+   "execution_count": 54,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -648,7 +648,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 31,
+   "execution_count": 55,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -670,7 +670,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 32,
+   "execution_count": 56,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -679,7 +679,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 33,
+   "execution_count": 57,
    "metadata": {
     "scrolled": true
    },
@@ -705,7 +705,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 34,
+   "execution_count": 58,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -723,7 +723,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 38,
+   "execution_count": 59,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -741,7 +741,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 39,
+   "execution_count": 60,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -762,7 +762,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 40,
+   "execution_count": 61,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -790,7 +790,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 41,
+   "execution_count": 62,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -835,7 +835,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 42,
+   "execution_count": 63,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -851,7 +851,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 53,
+   "execution_count": 64,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -884,7 +884,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 44,
+   "execution_count": 65,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -902,7 +902,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 45,
+   "execution_count": 66,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -945,7 +945,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 46,
+   "execution_count": 67,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -961,7 +961,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 47,
+   "execution_count": 68,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -977,7 +977,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 48,
+   "execution_count": 69,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -990,7 +990,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 49,
+   "execution_count": 70,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1008,7 +1008,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 50,
+   "execution_count": 71,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1024,7 +1024,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 51,
+   "execution_count": 72,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1033,7 +1033,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 52,
+   "execution_count": 73,
    "metadata": {},
    "outputs": [],
    "source": [

06_photo.ipynb

@@ -43,67 +43,48 @@
   },
   {
    "cell_type": "markdown",
-   "metadata": {
-    "tags": []
-   },
+   "metadata": {},
    "source": [
-    "## Installing libraries\n",
+    "## Reload the data\n",
     "\n",
-    "If you are running this notebook on Colab, you can run the following cell to install the libraries we'll use.\n",
-    "\n",
-    "If you are running this notebook on your own computer, you might have to install these libraries yourself.  See the instructions in the preface."
+    "You can [download the data from the previous lesson](https://github.com/AllenDowney/AstronomicalData/raw/main/data/gd1_data.hdf) or run the following cell, which downloads it if necessary."
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {
-    "tags": []
-   },
+   "execution_count": 47,
+   "metadata": {},
    "outputs": [],
    "source": [
-    "# If we're running on Colab, install libraries\n",
+    "from os.path import basename, exists\n",
     "\n",
-    "import sys\n",
-    "IN_COLAB = 'google.colab' in sys.modules\n",
+    "def download(url):\n",
+    "    filename = basename(url)\n",
+    "    if not exists(filename):\n",
+    "        from urllib.request import urlretrieve\n",
+    "        local, _ = urlretrieve(url, filename)\n",
+    "        print('Downloaded ' + local)\n",
     "\n",
-    "if IN_COLAB:\n",
-    "    !pip install wget"
+    "download('https://github.com/AllenDowney/AstronomicalData/raw/main/' +\n",
+    "         'data/gd1_data.hdf')"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## Reload the data\n",
-    "\n",
-    "The following cell downloads the photometry data we created in the previous notebook."
+    "Now we can reload `candidate_df`."
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "import os\n",
-    "from wget import download\n",
-    "\n",
-    "filename = 'gd1_data.hdf'\n",
-    "filepath = 'https://github.com/AllenDowney/AstronomicalData/raw/main/data/'\n",
-    "\n",
-    "if not os.path.exists(filename):\n",
-    "    print(download(filepath+filename))"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 3,
+   "execution_count": 48,
    "metadata": {},
    "outputs": [],
    "source": [
     "import pandas as pd\n",
     "\n",
+    "filename = 'gd1_data.hdf'\n",
     "candidate_df = pd.read_hdf(filename, 'candidate_df')"
    ]
   },
@@ -139,7 +120,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 49,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -195,7 +176,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 50,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -238,18 +219,12 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 6,
+   "execution_count": 51,
    "metadata": {},
    "outputs": [],
    "source": [
-    "import os\n",
-    "from wget import download\n",
-    "\n",
-    "filename = 'MIST_iso_5fd2532653c27.iso.cmd'\n",
-    "filepath = 'https://github.com/AllenDowney/AstronomicalData/raw/main/data/'\n",
-    "\n",
-    "if not os.path.exists(filename):\n",
-    "    print(download(filepath+filename))"
+    "download('https://github.com/AllenDowney/AstronomicalData/raw/main/' +\n",
+    "         'data/MIST_iso_5fd2532653c27.iso.cmd')"
    ]
   },
   {
@@ -261,18 +236,12 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 52,
    "metadata": {},
    "outputs": [],
    "source": [
-    "import os\n",
-    "from wget import download\n",
-    "\n",
-    "filename = 'read_mist_models.py'\n",
-    "filepath = 'https://github.com/jieunchoi/MIST_codes/raw/master/scripts/'\n",
-    "\n",
-    "if not os.path.exists(filename):\n",
-    "    print(download(filepath+filename))"
+    "download('https://github.com/jieunchoi/MIST_codes/raw/master/scripts/' +\n",
+    "         'read_mist_models.py')"
    ]
   },
   {
@@ -284,7 +253,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
+   "execution_count": 53,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -303,7 +272,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 9,
+   "execution_count": 54,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -319,7 +288,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 10,
+   "execution_count": 55,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -335,7 +304,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 11,
+   "execution_count": 56,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -351,7 +320,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 12,
+   "execution_count": 57,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -367,7 +336,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 13,
+   "execution_count": 58,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -383,7 +352,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 14,
+   "execution_count": 59,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -399,7 +368,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 15,
+   "execution_count": 60,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -415,7 +384,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 16,
+   "execution_count": 61,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -425,7 +394,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 17,
+   "execution_count": 62,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -446,7 +415,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 18,
+   "execution_count": 63,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -467,7 +436,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 19,
+   "execution_count": 64,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -484,7 +453,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 20,
+   "execution_count": 65,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -505,7 +474,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 21,
+   "execution_count": 66,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -527,7 +496,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 22,
+   "execution_count": 67,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -546,18 +515,12 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 23,
+   "execution_count": 68,
    "metadata": {},
    "outputs": [],
    "source": [
-    "import os\n",
-    "from wget import download\n",
-    "\n",
-    "filename = 'gd1_isochrone.hdf5'\n",
-    "filepath = 'https://github.com/AllenDowney/AstronomicalData/raw/main/data/'\n",
-    "\n",
-    "if not os.path.exists(filename):\n",
-    "    print(download(filepath+filename))"
+    "download('https://github.com/AllenDowney/AstronomicalData/raw/main/data/' +\n",
+    "         'gd1_isochrone.hdf5')"
    ]
   },
   {
@@ -569,10 +532,11 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 24,
+   "execution_count": 69,
    "metadata": {},
    "outputs": [],
    "source": [
+    "filename = 'gd1_isochrone.hdf5'\n",
     "iso_df = pd.read_hdf(filename, 'iso_df')\n",
     "iso_df.head()"
    ]
@@ -586,7 +550,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 25,
+   "execution_count": 70,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -609,7 +573,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 26,
+   "execution_count": 71,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -628,7 +592,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 27,
+   "execution_count": 72,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -647,7 +611,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 28,
+   "execution_count": 73,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -667,7 +631,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 29,
+   "execution_count": 74,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -685,7 +649,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 30,
+   "execution_count": 75,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -712,7 +676,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 31,
+   "execution_count": 76,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -746,7 +710,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 32,
+   "execution_count": 77,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -763,7 +727,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 33,
+   "execution_count": 78,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -780,7 +744,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 34,
+   "execution_count": 79,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -797,7 +761,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 35,
+   "execution_count": 80,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -816,7 +780,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 36,
+   "execution_count": 81,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -837,7 +801,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 37,
+   "execution_count": 82,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -854,7 +818,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 38,
+   "execution_count": 83,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -889,7 +853,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 39,
+   "execution_count": 84,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -909,7 +873,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 40,
+   "execution_count": 85,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -930,7 +894,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 41,
+   "execution_count": 86,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -947,7 +911,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 42,
+   "execution_count": 87,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -963,7 +927,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 43,
+   "execution_count": 88,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -979,7 +943,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 44,
+   "execution_count": 89,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1003,7 +967,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 45,
+   "execution_count": 90,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1043,7 +1007,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 46,
+   "execution_count": 91,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1053,7 +1017,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 47,
+   "execution_count": 92,
    "metadata": {},
    "outputs": [],
    "source": [

07_plot.ipynb

@@ -38,36 +38,6 @@
     "* Generate a figure with multiple subplots."
    ]
   },
-  {
-   "cell_type": "markdown",
-   "metadata": {
-    "tags": []
-   },
-   "source": [
-    "## Installing libraries\n",
-    "\n",
-    "If you are running this notebook on Colab, you can run the following cell to install the libraries we'll use.\n",
-    "\n",
-    "If you are running this notebook on your own computer, you might have to install these libraries yourself.  See the instructions in the preface."
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {
-    "tags": []
-   },
-   "outputs": [],
-   "source": [
-    "# If we're running on Colab, install libraries\n",
-    "\n",
-    "import sys\n",
-    "IN_COLAB = 'google.colab' in sys.modules\n",
-    "\n",
-    "if IN_COLAB:\n",
-    "    !pip install wget"
-   ]
-  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -113,7 +83,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 30,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -126,39 +96,50 @@
    "source": [
     "## Plotting GD-1\n",
     "\n",
-    "Let's start with the panel in the lower left.  The following cell reloads the data."
+    "Let's start with the panel in the lower left.  You can [download the data from the previous lesson](https://github.com/AllenDowney/AstronomicalData/raw/main/data/gd1_data.hdf) or run the following cell, which downloads it if necessary."
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 3,
+   "execution_count": 31,
    "metadata": {},
    "outputs": [],
    "source": [
-    "import os\n",
-    "from wget import download\n",
+    "from os.path import basename, exists\n",
     "\n",
-    "filename = 'gd1_data.hdf'\n",
-    "path = 'https://github.com/AllenDowney/AstronomicalData/raw/main/data/'\n",
+    "def download(url):\n",
+    "    filename = basename(url)\n",
+    "    if not exists(filename):\n",
+    "        from urllib.request import urlretrieve\n",
+    "        local, _ = urlretrieve(url, filename)\n",
+    "        print('Downloaded ' + local)\n",
     "\n",
-    "if not os.path.exists(filename):\n",
-    "    print(download(path+filename))"
+    "download('https://github.com/AllenDowney/AstronomicalData/raw/main/' +\n",
+    "         'data/gd1_data.hdf')"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Now we can reload `winner_df`"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 32,
    "metadata": {},
    "outputs": [],
    "source": [
     "import pandas as pd\n",
     "\n",
+    "filename = 'gd1_data.hdf'\n",
     "winner_df = pd.read_hdf(filename, 'winner_df')"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 33,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -186,7 +167,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 6,
+   "execution_count": 34,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -228,7 +209,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 35,
    "metadata": {
     "tags": []
    },
@@ -280,7 +261,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 8,
+   "execution_count": 36,
    "metadata": {
     "tags": []
    },
@@ -302,7 +283,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 9,
+   "execution_count": 37,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -318,7 +299,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 10,
+   "execution_count": 38,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -356,7 +337,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 11,
+   "execution_count": 39,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -403,23 +384,17 @@
    "source": [
     "If you can't find a style sheet that's exactly what you want, you can make your own.  This repository includes a style sheet called `az-paper-twocol.mplstyle`, with customizations chosen by Azalee Bostroem for publication in astronomy journals.\n",
     "\n",
-    "The following cell downloads the style sheet."
+    "You can [download the style sheet](https://github.com/AllenDowney/AstronomicalData/raw/main/az-paper-twocol.mplstyle) or run the following cell, which downloads it if necessary."
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 12,
+   "execution_count": 40,
    "metadata": {},
    "outputs": [],
    "source": [
-    "import os\n",
-    "from wget import download\n",
-    "\n",
-    "filename = 'az-paper-twocol.mplstyle'\n",
-    "path = 'https://github.com/AllenDowney/AstronomicalData/raw/main/'\n",
-    "\n",
-    "if not os.path.exists(filename):\n",
-    "    print(download(path+filename))"
+    "download('https://github.com/AllenDowney/AstronomicalData/raw/main/' +\n",
+    "         'az-paper-twocol.mplstyle')"
    ]
   },
   {
@@ -487,7 +462,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 13,
+   "execution_count": 41,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -515,7 +490,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 14,
+   "execution_count": 42,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -555,7 +530,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 15,
+   "execution_count": 43,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -572,7 +547,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 16,
+   "execution_count": 44,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -596,7 +571,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 17,
+   "execution_count": 45,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -615,7 +590,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 18,
+   "execution_count": 46,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -649,7 +624,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 19,
+   "execution_count": 47,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -667,7 +642,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 20,
+   "execution_count": 48,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -684,7 +659,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 21,
+   "execution_count": 49,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -710,7 +685,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 22,
+   "execution_count": 50,
    "metadata": {
     "scrolled": true
    },
@@ -730,7 +705,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 23,
+   "execution_count": 51,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -763,7 +738,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 24,
+   "execution_count": 52,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -779,7 +754,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 25,
+   "execution_count": 53,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -801,7 +776,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 26,
+   "execution_count": 54,
    "metadata": {
     "tags": []
    },
@@ -831,7 +806,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 27,
+   "execution_count": 55,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -882,7 +857,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 28,
+   "execution_count": 56,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -925,7 +900,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 29,
+   "execution_count": 57,
    "metadata": {},
    "outputs": [],
    "source": [