Solutions to tutorial3 ES1

tutorials/SOL1/ES1_Solutions_Tutorial3.ipynb

+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import networkx as nx\n",
+    "%matplotlib inline"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "G = nx.read_graphml('./datasets/openflights/openflights_usa.graphml.gz')"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# EXERCISE 1\n",
+    "\n",
+    "Is there a direct flight between Indianapolis and Fairbanks, Alaska (FAI)? A direct flight is one with no intermediate stops."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Answer 1"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "'FAI' in list(G.neighbors('IND'))"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "'FAI' does not belong to the neighbours of 'IND', so there is no direct flight between the two airports."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# EXERCISE 2\n",
+    "\n",
+    "If I wanted to fly from Indianapolis to Fairbanks, Alaska what would be an itinerary with the fewest number of flights?"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Answer 2"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "nx.has_path(G, 'IND', 'FAI')"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "So we know that there is a path between the two airports"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "shortest_path_IND_FAI = nx.shortest_path(G, 'IND', 'FAI')\n",
+    "for i in shortest_path_IND_FAI:\n",
+    "    print(G.nodes[i])"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "So the itinerary between Indianapolis and Fairbanks with the fewest number of flights passes through Boston and Seattle."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# EXERCISE 3\n",
+    "\n",
+    "Is it possible to travel from any airport in the US to any other airport in the US, possibly using connecting flights? In other words, does there exist a path in the network between every possible pair of airports?"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "components = list(nx.connected_components(G))\n",
+    "len(components)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "The graph contains multiple connected components, so it is not possible to fly from any airport in the US to any other airport in the US (possibly using connecting flights)."
+   ]
+  }
+ ],
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