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<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Interactive Mapping</title>
<style>
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height: 0; overflow: visible; } body input { font: inherit; margin: 0; } body input { overflow: visible; } body [type="checkbox"] { box-sizing: border-box; padding: 0; } body * { box-sizing: border-box; } body input { font-family: inherit; font-size: inherit; line-height: inherit; } body a { color: #4078c0; text-decoration: none; } body a:hover, body a:active { text-decoration: underline; } body strong { font-weight: 600; } body hr { height: 0; margin: 15px 0; overflow: hidden; background: transparent; border: 0; border-bottom: 1px solid #ddd; } body hr::before { display: table; content: ""; } body hr::after { display: table; clear: both; content: ""; } body table { border-spacing: 0; border-collapse: collapse; } body td, body th { padding: 0; } body h1, body h2, body h3, body h4, body h5, body h6 { margin-top: 0; margin-bottom: 0; } body h1 { font-size: 32px; font-weight: 600; } body h2 { font-size: 24px; font-weight: 600; } body h3 { font-size: 20px; font-weight: 600; } body h4 { font-size: 16px; 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text-decoration: none; } body .anchor { float: left; padding-right: 4px; margin-left: -20px; line-height: 1; } body .anchor:focus { outline: none; } body p, body blockquote, body ul, body ol, body dl, body table, body pre { margin-top: 0; margin-bottom: 16px; } body hr { height: 0.25em; padding: 0; margin: 24px 0; background-color: #e7e7e7; border: 0; } body blockquote { padding: 0 1em; color: #777; border-left: 0.25em solid #ddd; } body blockquote>:first-child { margin-top: 0; } body blockquote>:last-child { margin-bottom: 0; } body kbd { display: inline-block; padding: 3px 5px; font-size: 11px; line-height: 10px; color: #555; vertical-align: middle; background-color: #fcfcfc; border: solid 1px #ccc; border-bottom-color: #bbb; border-radius: 3px; box-shadow: inset 0 -1px 0 #bbb; } body h1, body h2, body h3, body h4, body h5, body h6 { margin-top: 24px; margin-bottom: 16px; font-weight: 600; line-height: 1.25; } body h1 .octicon-link, body h2 .octicon-link, body h3 .octicon-link, body h4 .octicon-link, body h5 .octicon-link, body h6 .octicon-link { color: #000; vertical-align: middle; visibility: hidden; } body h1:hover .anchor, body h2:hover .anchor, body h3:hover .anchor, body h4:hover .anchor, body h5:hover .anchor, body h6:hover .anchor { text-decoration: none; } body h1:hover .anchor .octicon-link, body h2:hover .anchor .octicon-link, body h3:hover .anchor .octicon-link, body h4:hover .anchor .octicon-link, body h5:hover .anchor .octicon-link, body h6:hover .anchor .octicon-link { visibility: visible; } body h1 { padding-bottom: 0.3em; font-size: 2em; border-bottom: 1px solid #eee; } body h2 { padding-bottom: 0.3em; font-size: 1.5em; border-bottom: 1px solid #eee; } body h3 { font-size: 1.25em; } body h4 { font-size: 1em; } body h5 { font-size: 0.875em; } body h6 { font-size: 0.85em; color: #777; } body ul, body ol { padding-left: 2em; } body ul ul, body ul ol, body ol ol, body ol ul { margin-top: 0; margin-bottom: 0; } body li>p { margin-top: 16px; } body li+li { margin-top: 0.25em; } body dl { padding: 0; } body dl dt { padding: 0; margin-top: 16px; font-size: 1em; font-style: italic; font-weight: bold; } body dl dd { padding: 0 16px; margin-bottom: 16px; } body table { display: block; width: 100%; overflow: auto; } body table th { font-weight: bold; } body table th, body table td { padding: 6px 13px; border: 1px solid #ddd; } body table tr { background-color: #fff; border-top: 1px solid #ccc; } /* body table tr:nth-child(2n) { background-color: #f8f8f8; } */ body img { max-width: 100%; box-sizing: content-box; background-color: #fff; } body code { padding: 0; padding-top: 0.2em; padding-bottom: 0.2em; margin: 0; font-size: 85%; background-color: rgba(0,0,0,0.04); border-radius: 3px; } body code::before, body code::after { letter-spacing: -0.2em; content: "\00a0"; } body pre { word-wrap: normal; } body pre>code { padding: 0; margin: 0; font-size: 100%; word-break: normal; white-space: pre; background: transparent; border: 0; } body .highlight { margin-bottom: 16px; } body .highlight pre { margin-bottom: 0; word-break: normal; } body .highlight pre, body pre { padding: 16px; overflow: auto; font-size: 85%; line-height: 1.45; background-color: #f7f7f7; border-radius: 3px; } body pre code { display: inline; max-width: auto; padding: 0; margin: 0; overflow: visible; line-height: inherit; word-wrap: normal; background-color: transparent; border: 0; } body pre code::before, body pre code::after { content: normal; } body .pl-0 { padding-left: 0 !important; } body .pl-1 { padding-left: 3px !important; } body .pl-2 { padding-left: 6px !important; } body .pl-3 { padding-left: 12px !important; } body .pl-4 { padding-left: 24px !important; } body .pl-5 { padding-left: 36px !important; } body .pl-6 { padding-left: 48px !important; } body .full-commit .btn-outline:not(:disabled):hover { color: #4078c0; border: 1px solid #4078c0; } body kbd { display: inline-block; padding: 3px 5px; font: 11px Consolas, "Liberation Mono", Menlo, Courier, monospace; line-height: 10px; color: #555; vertical-align: middle; background-color: #fcfcfc; border: solid 1px #ccc; border-bottom-color: #bbb; border-radius: 3px; box-shadow: inset 0 -1px 0 #bbb; } body :checked+.radio-label { position: relative; z-index: 1; border-color: #4078c0; } body .task-list-item { list-style-type: none; } body .task-list-item+.task-list-item { margin-top: 3px; } body .task-list-item input { margin: 0 0.2em 0.25em -1.6em; vertical-align: middle; } body hr { border-bottom-color: #eee; }
</style>
</head>
<body class="vscode-body vscode-light">
<p>Tutorials: <a href="tutorial-1.html">HTML/CSS/JS</a> | <a href="tutorial-2.html">Leaflet</a> | <a href="tutorial-3.html">D3</a> | Visualizing spatial-temporal data 1 | <a href="tutorial-5.html">Visualizing spatial-temporal data 2</a></p>
<h1 id="interactive-mapping">Interactive Mapping</h1>
<h2 id="tutorial-4-interactive-visualization-of-spatial-temporal-data">Tutorial 4. Interactive Visualization of Spatial-Temporal Data</h2>
<p><em>Ningchuan Xiao</em></p>
<p>The goals of this workshop include</p>
<ul>
<li>Time scale and axis</li>
<li>Interactive features in d3 graphs and leaflet maps</li>
<li>Linking between graphs and maps</li>
</ul>
<h2 id="spatial-temporal-data">Spatial-temporal data</h2>
<p>We are going to use the data of 24 hours of Blitz (bombing of London) on September 7, 1940. The data source is <a href="http://bombsight.org/data/sources/">http://bombsight.org/data/sources/</a>. A former student, Maxfield Barach, has geocoded the original data and reported that only 708 of the 843 bomb sights can be geocoded. My further clean-up of the data found that only 706 were good. This geocoded data is saved in a tab separated file (TSV) called <a href="bombs.tsv">bombs.tsv</a> and the first three lines are like this:</p>
<pre><code><code><div>order time location type details lng lat
1 0:08 43 Southwark Park Road, SE16, London, UK IB Grocers: 3x2 roof damaged -0.068463 51.494531
2 0:10 49 Southwark Park road, Bermondsey, SE16, London, UK IB Bakers: 3x2 roof damaged -0.058463 51.494532
</div></code></code></pre>
<h2 id="map-the-bombs">Map the bombs</h2>
<p>We first need to write the following HTML file. Let's call it <strong>bombs1.html</strong>.</p>
<pre><code class="language-html"><div><span class="hljs-meta"><!DOCTYPE <span class="hljs-meta-keyword">html</span>></span>
<span class="hljs-tag"><<span class="hljs-name">html</span> <span class="hljs-attr">lang</span>=<span class="hljs-string">"en"</span>></span>
<span class="hljs-tag"><<span class="hljs-name">head</span>></span>
<span class="hljs-tag"><<span class="hljs-name">meta</span> <span class="hljs-attr">charset</span>=<span class="hljs-string">"utf-8"</span>></span>
<span class="hljs-tag"><<span class="hljs-name">style</span>></span><span class="css">
<span class="hljs-selector-id">#map</span> { <span class="hljs-attribute">height</span>: <span class="hljs-number">500px</span>; }
<span class="hljs-selector-tag">body</span> { <span class="hljs-attribute">padding</span>: <span class="hljs-number">0</span>; <span class="hljs-attribute">margin</span>: <span class="hljs-number">0</span> }
</span><span class="hljs-tag"></<span class="hljs-name">style</span>></span>
<span class="hljs-tag"><<span class="hljs-name">title</span>></span>Bombs map<span class="hljs-tag"></<span class="hljs-name">title</span>></span>
<span class="hljs-tag"><<span class="hljs-name">link</span> <span class="hljs-attr">rel</span>=<span class="hljs-string">"stylesheet"</span> <span class="hljs-attr">href</span>=<span class="hljs-string">"https://unpkg.com/leaflet@1.8.0/dist/leaflet.css"</span>
<span class="hljs-attr">integrity</span>=<span class="hljs-string">"sha512-hoalWLoI8r4UszCkZ5kL8vayOGVae1oxXe/2A4AO6J9+580uKHDO3JdHb7NzwwzK5xr/Fs0W40kiNHxM9vyTtQ=="</span>
<span class="hljs-attr">crossorigin</span>=<span class="hljs-string">""</span>/></span>
<span class="hljs-comment"><!-- Make sure you put this AFTER Leaflet's CSS --></span>
<span class="hljs-tag"><<span class="hljs-name">script</span> <span class="hljs-attr">src</span>=<span class="hljs-string">"https://unpkg.com/leaflet@1.8.0/dist/leaflet.js"</span>
<span class="hljs-attr">integrity</span>=<span class="hljs-string">"sha512-BB3hKbKWOc9Ez/TAwyWxNXeoV9c1v6FIeYiBieIWkpLjauysF18NzgR1MBNBXf8/KABdlkX68nAhlwcDFLGPCQ=="</span>
<span class="hljs-attr">crossorigin</span>=<span class="hljs-string">""</span>></span><span class="hljs-tag"></<span class="hljs-name">script</span>></span>
<span class="hljs-tag"><<span class="hljs-name">script</span> <span class="hljs-attr">src</span>=<span class="hljs-string">"https://d3js.org/d3.v7.min.js"</span>></span><span class="hljs-tag"></<span class="hljs-name">script</span>></span>
<span class="hljs-tag"></<span class="hljs-name">head</span>></span>
<span class="hljs-tag"><<span class="hljs-name">body</span>></span>
<span class="hljs-tag"><<span class="hljs-name">h2</span>></span>Bombs Map<span class="hljs-tag"></<span class="hljs-name">h2</span>></span>
<span class="hljs-tag"><<span class="hljs-name">div</span> <span class="hljs-attr">id</span>=<span class="hljs-string">"map"</span>></span><span class="hljs-tag"></<span class="hljs-name">div</span>></span>
<span class="hljs-tag"><<span class="hljs-name">div</span> <span class="hljs-attr">id</span>=<span class="hljs-string">"debug"</span>></span><span class="hljs-tag"></<span class="hljs-name">div</span>></span>
<span class="hljs-tag"><<span class="hljs-name">script</span> <span class="hljs-attr">src</span>=<span class="hljs-string">"bombs1.js"</span> <span class="hljs-attr">type</span>=<span class="hljs-string">"text/javascript"</span>></span>
<span class="hljs-tag"></<span class="hljs-name">script</span>></span>
<span class="hljs-tag"></<span class="hljs-name">body</span>></span>
<span class="hljs-tag"></<span class="hljs-name">html</span>></span>
</div></code></pre>
<p>Now as indicated in the above HTML file, we write the javascript file called <strong>bombs1.js</strong>. We especially focus on how the data is processed by called <strong>d3.tsv</strong>.</p>
<pre><code class="language-js"><div><span class="hljs-comment">// Data source: http://bombsight.org/data/sources/</span>
<span class="hljs-comment">// 24 hours of Blitz Sept 7th 1940</span>
<span class="hljs-keyword">var</span> parseTime = d3.timeParse(<span class="hljs-string">"%B %d, %Y %I:%M %Z"</span>);
<span class="hljs-keyword">var</span> bombs_data;
<span class="hljs-keyword">var</span> bombs_geojson;
<span class="hljs-keyword">var</span> map;
<span class="hljs-keyword">var</span> bombs_layer;
<span class="hljs-keyword">var</span> default_bombs_style = {
<span class="hljs-attr">color</span>: <span class="hljs-string">"none"</span>,
<span class="hljs-attr">radius</span>: <span class="hljs-number">6</span>,
<span class="hljs-attr">fillColor</span>: <span class="hljs-string">"red"</span>,
<span class="hljs-attr">opacity</span>: <span class="hljs-number">1</span>,
<span class="hljs-attr">fillOpacity</span>: <span class="hljs-number">0.3</span>,
<span class="hljs-attr">weight</span>: <span class="hljs-number">0</span>
};
<span class="hljs-keyword">var</span> highlight_bombs_style = {
<span class="hljs-attr">fillColor</span>: <span class="hljs-string">'yellow'</span>,
<span class="hljs-attr">color</span>: <span class="hljs-string">"grey"</span>,
<span class="hljs-attr">fillOpacity</span>: <span class="hljs-number">0.8</span>,
<span class="hljs-attr">weight</span>: <span class="hljs-number">2</span>
}
d3.tsv(<span class="hljs-string">"bombs.tsv"</span>).then(<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">handle_bombs</span>(<span class="hljs-params">data</span>) </span>{
alert(<span class="hljs-built_in">Object</span>.keys(data));
alert(data)
bombs_geojson = {
<span class="hljs-string">"type"</span>: <span class="hljs-string">"FeatureCollection"</span>,
<span class="hljs-string">"features"</span>: []
};
data.forEach(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d, i</span>) </span>{
d.order = +d.order;
d.lng = +d.lng;
d.lat = +d.lat;
d.type = (d==<span class="hljs-string">"-"</span>?<span class="hljs-string">"Other"</span>:d.type);
d.time = parseTime(<span class="hljs-string">"September 7, 1940 "</span> + d.time + <span class="hljs-string">" -0000"</span>);
bombs_geojson.features[i] = {
<span class="hljs-string">"type"</span>: <span class="hljs-string">"Feature"</span>,
<span class="hljs-string">"geometry"</span>: {
<span class="hljs-string">"type"</span>: <span class="hljs-string">"Point"</span>,
<span class="hljs-string">"coordinates"</span>: [d.lng, d.lat]
},
<span class="hljs-string">"properties"</span>: {
<span class="hljs-string">"id"</span>: i
}
};
});
bombs_data = data;
make_maps();
});
<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">make_maps</span>(<span class="hljs-params"></span>) </span>{
map = L.map(<span class="hljs-string">'map'</span>); <span class="hljs-comment">// create a map in the "map" div</span>
map.setView([<span class="hljs-number">51.5</span>, -<span class="hljs-number">0.1</span>], <span class="hljs-number">10</span>); <span class="hljs-comment">// set the view to central Ohio and zoom</span>
<span class="hljs-comment">// create an OpenStreetMap tile layer</span>
<span class="hljs-keyword">var</span> osmMapnik = L.tileLayer(<span class="hljs-string">'http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png'</span>, {
<span class="hljs-attr">attribution</span>: <span class="hljs-string">'&copy; <a href="http://osm.org/copyright">OpenStreetMap</a>contributors'</span>
});
<span class="hljs-comment">// create another layer using the cartodb service</span>
<span class="hljs-keyword">var</span> cartoLight = L.tileLayer(<span class="hljs-string">"https://cartodb-basemaps-{s}.global.ssl.fastly.net/light_all/{z}/{x}/{y}.png"</span>, {
<span class="hljs-attr">attribution</span>: <span class="hljs-string">'&copy; <a href="http://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors, &copy; <a href="https://cartodb.com/attributions">CartoDB</a>'</span>
});
<span class="hljs-keyword">var</span> baseMaps = {
<span class="hljs-string">"Street map light"</span>: cartoLight,
<span class="hljs-string">"OpenStreetMap"</span>: osmMapnik
};
<span class="hljs-keyword">var</span> layersControl = <span class="hljs-keyword">new</span> L.Control.Layers(baseMaps, <span class="hljs-literal">null</span>, {<span class="hljs-attr">collapsed</span>: <span class="hljs-literal">true</span>, <span class="hljs-attr">position</span>: <span class="hljs-string">'bottomleft'</span>});
map.addControl(layersControl);
map.addLayer(cartoLight, <span class="hljs-literal">true</span>);
bombs_layer = L.geoJson(bombs_geojson, {
<span class="hljs-attr">pointToLayer</span>: <span class="hljs-function"><span class="hljs-keyword">function</span> (<span class="hljs-params">feature, latlng</span>) </span>{
<span class="hljs-keyword">return</span> L.circleMarker(latlng);
},
<span class="hljs-attr">style</span>: <span class="hljs-function"><span class="hljs-keyword">function</span> (<span class="hljs-params">feature</span>) </span>{
<span class="hljs-keyword">return</span> {
<span class="hljs-attr">color</span>: <span class="hljs-string">"none"</span>,
<span class="hljs-attr">radius</span>: <span class="hljs-number">6</span>,
<span class="hljs-attr">fillColor</span>: <span class="hljs-string">"#F65"</span>,
<span class="hljs-attr">opacity</span>: <span class="hljs-number">1</span>,
<span class="hljs-attr">fillOpacity</span>: <span class="hljs-number">0.3</span>,
<span class="hljs-attr">weight</span>: <span class="hljs-number">0</span>
};
},
<span class="hljs-attr">onEachFeature</span>: onEachBombsFeature
}).addTo(map);
layersControl.addOverlay(bombs_layer, <span class="hljs-string">"Bombs"</span>);
}
<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">onEachBombsFeature</span>(<span class="hljs-params">feature, layer</span>) </span>{
layer.on({
<span class="hljs-attr">mouseover</span>: <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">e</span>) </span>{
<span class="hljs-keyword">var</span> layer = e.target;
<span class="hljs-keyword">var</span> feature = layer.feature;
<span class="hljs-keyword">var</span> feature_id = feature.properties.id;
layer.setStyle(highlight_bombs_style);
<span class="hljs-keyword">if</span> (!L.Browser.ie && !L.Browser.opera) {
layer.bringToFront();
}
d3.select(<span class="hljs-string">"#debug"</span>).html(bombs_data[feature_id].details);
},
<span class="hljs-attr">mouseout</span>: <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">e</span>) </span>{
bombs_layer.resetStyle(e.target);
}
})
}
</div></code></pre>
<h2 id="draw-a-barchart-for-types-of-bombs">Draw a barchart for types of bombs</h2>
<p>We save the following code to a file called <strong>bombs2.html</strong>.</p>
<pre><code class="language-html"><div><span class="hljs-meta"><!DOCTYPE <span class="hljs-meta-keyword">html</span>></span>
<span class="hljs-tag"><<span class="hljs-name">html</span> <span class="hljs-attr">lang</span>=<span class="hljs-string">"en"</span>></span>
<span class="hljs-tag"><<span class="hljs-name">head</span>></span>
<span class="hljs-tag"><<span class="hljs-name">meta</span> <span class="hljs-attr">charset</span>=<span class="hljs-string">"utf-8"</span>></span>
<span class="hljs-tag"><<span class="hljs-name">style</span>></span><span class="css">
<span class="hljs-selector-class">.axis</span> path,
<span class="hljs-selector-class">.axis</span> line {
fill: none;
stroke: black;
shape-rendering: crispEdges;
}
<span class="hljs-selector-class">.axis</span> text {
<span class="hljs-attribute">font-family</span>: sans-serif;
<span class="hljs-attribute">font-size</span>: <span class="hljs-number">11px</span>;
}
<span class="hljs-selector-class">.x</span><span class="hljs-selector-class">.axis</span> path {
<span class="hljs-attribute">display</span>: none;
}
</span><span class="hljs-tag"></<span class="hljs-name">style</span>></span>
<span class="hljs-tag"><<span class="hljs-name">title</span>></span>Bomb types<span class="hljs-tag"></<span class="hljs-name">title</span>></span>
<span class="hljs-tag"><<span class="hljs-name">script</span> <span class="hljs-attr">src</span>=<span class="hljs-string">"https://d3js.org/d3.v7.min.js"</span>></span><span class="hljs-tag"></<span class="hljs-name">script</span>></span>
<span class="hljs-tag"></<span class="hljs-name">head</span>></span>
<span class="hljs-tag"><<span class="hljs-name">body</span>></span>
<span class="hljs-tag"><<span class="hljs-name">h2</span>></span>Bomb Types<span class="hljs-tag"></<span class="hljs-name">h2</span>></span>
<span class="hljs-tag"><<span class="hljs-name">script</span> <span class="hljs-attr">src</span>=<span class="hljs-string">"bombs2.js"</span> <span class="hljs-attr">type</span>=<span class="hljs-string">"text/javascript"</span>></span>
<span class="hljs-tag"></<span class="hljs-name">script</span>></span>
<span class="hljs-tag"></<span class="hljs-name">body</span>></span>
<span class="hljs-tag"></<span class="hljs-name">html</span>></span>
</div></code></pre>
<p>Then we need to following javascript code saved in <strong>bombs2.js</strong>. This is a typical use of D3 for barcharts. We will pay attention to how the behaviors of <code>mouseover</code> and <code>mouseout</code> are defined.</p>
<pre><code class="language-js"><div><span class="hljs-comment">// This is where we put the good stuff using D3</span>
<span class="hljs-comment">// Data source: http://bombsight.org/data/sources/</span>
<span class="hljs-comment">// 24 hours of Blitz Sept 7th 1940</span>
<span class="hljs-keyword">var</span> parseTime = d3.timeParse(<span class="hljs-string">"%B %d, %Y %I:%M %Z"</span>);
<span class="hljs-keyword">var</span> bombs_data;
<span class="hljs-keyword">var</span> bombs_types = {};
<span class="hljs-keyword">var</span> bombs_types_array;
<span class="hljs-keyword">var</span> keys;
<span class="hljs-keyword">var</span> svg;
<span class="hljs-keyword">var</span> rects;
d3.tsv(<span class="hljs-string">"bombs.tsv"</span>).then(<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">handle_bombs</span>(<span class="hljs-params">data</span>) </span>{
data.forEach(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d, i</span>) </span>{
d.order = +d[<span class="hljs-string">"order"</span>];
d.lng = +d[<span class="hljs-string">"lng"</span>];
d.lat = +d[<span class="hljs-string">"lat"</span>];
d.type = (d.type==<span class="hljs-string">"-"</span>?<span class="hljs-string">"Other"</span>:d.type);
d.time = parseTime(<span class="hljs-string">"September 7, 1940 "</span> + d.time + <span class="hljs-string">" -0400"</span>);
<span class="hljs-keyword">if</span> (d.type <span class="hljs-keyword">in</span> bombs_types)
bombs_types[d.type] += <span class="hljs-number">1</span>;
<span class="hljs-keyword">else</span>
bombs_types[d.type] = <span class="hljs-number">1</span>
});
bombs_data = data;
<span class="hljs-comment">// alert(data[0].time + " " + data[0].details);</span>
keys = <span class="hljs-built_in">Object</span>.keys(bombs_types);
bombs_types_array = keys.map(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">v</span>) </span>{ <span class="hljs-keyword">return</span> [v, bombs_types[v]]; });
make_barchart();
});
<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">make_barchart</span>(<span class="hljs-params"></span>) </span>{
<span class="hljs-keyword">var</span> total_w = <span class="hljs-number">500</span>;
<span class="hljs-keyword">var</span> total_h = <span class="hljs-number">200</span>;
<span class="hljs-keyword">var</span> margin = {<span class="hljs-attr">top</span>: <span class="hljs-number">15</span>, <span class="hljs-attr">right</span>: <span class="hljs-number">20</span>, <span class="hljs-attr">bottom</span>: <span class="hljs-number">50</span>, <span class="hljs-attr">left</span>: <span class="hljs-number">20</span>};
<span class="hljs-keyword">var</span> w = total_w - margin.left - margin.right;
<span class="hljs-keyword">var</span> h = total_h - margin.top - margin.bottom;
svg = d3.select(<span class="hljs-string">"body"</span>)
.append(<span class="hljs-string">"svg"</span>)
.attr(<span class="hljs-string">"width"</span>, w + margin.left + margin.right)
.attr(<span class="hljs-string">"height"</span>, h + margin.top + margin.bottom);
<span class="hljs-keyword">var</span> yScale = d3.scaleLinear().
domain([<span class="hljs-number">0</span>, d3.max(bombs_types_array, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> d[<span class="hljs-number">1</span>]; })]).
range([h, margin.top]);
<span class="hljs-keyword">var</span> yAxis = d3.axisLeft()
.scale(yScale)
.ticks(<span class="hljs-number">3</span>);
xScale = d3.scaleBand()
.domain(bombs_types_array.map(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> d[<span class="hljs-number">0</span>]; }))
<span class="hljs-comment">// .domain(keys)</span>
.rangeRound([margin.left, w], <span class="hljs-number">0.05</span>);
xAxis = d3.axisBottom()
.scale(xScale);
rects = svg.selectAll(<span class="hljs-string">"rect"</span>)
.data(bombs_types_array)
.enter()
.append(<span class="hljs-string">"rect"</span>)
.attr(<span class="hljs-string">"x"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d, i</span>) </span>{<span class="hljs-keyword">return</span> xScale(d[<span class="hljs-number">0</span>]);})
.attr(<span class="hljs-string">"y"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{<span class="hljs-keyword">return</span> yScale(d[<span class="hljs-number">1</span>]);} )
.attr(<span class="hljs-string">"height"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{<span class="hljs-keyword">return</span> h-yScale(d[<span class="hljs-number">1</span>]);})
.attr(<span class="hljs-string">"width"</span>, xScale.bandwidth())
.attr(<span class="hljs-string">"fill"</span>, <span class="hljs-string">"steelblue"</span>);
rects.on(<span class="hljs-string">"mouseover"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d,i</span>) </span>{
d3.select(<span class="hljs-built_in">this</span>).style(<span class="hljs-string">'fill'</span>, <span class="hljs-string">'red'</span>);
})
.on(<span class="hljs-string">"mouseout"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d, i</span>) </span>{
d3.select(<span class="hljs-built_in">this</span>).style(<span class="hljs-string">"fill"</span>, <span class="hljs-string">"steelblue"</span>);
})
svg.append(<span class="hljs-string">"g"</span>)
.attr(<span class="hljs-string">"class"</span>, <span class="hljs-string">"axis"</span>)
.attr(<span class="hljs-string">"transform"</span>, <span class="hljs-string">"translate("</span> + margin.left + <span class="hljs-string">","</span> + <span class="hljs-number">0</span> +<span class="hljs-string">")"</span>)
.call(yAxis);
svg.append(<span class="hljs-string">"g"</span>)
.attr(<span class="hljs-string">"class"</span>, <span class="hljs-string">"x axis"</span>)
.attr(<span class="hljs-string">"transform"</span>, <span class="hljs-string">"translate(0,"</span> + h + <span class="hljs-string">")"</span>)
.call(xAxis)
.selectAll(<span class="hljs-string">"text"</span>)
.attr(<span class="hljs-string">"y"</span>, <span class="hljs-number">5</span>)
.attr(<span class="hljs-string">"x"</span>, <span class="hljs-number">5</span>)
.attr(<span class="hljs-string">"transform"</span>, <span class="hljs-string">"rotate(45)"</span>)
.style(<span class="hljs-string">"text-anchor"</span>, <span class="hljs-string">"start"</span>);
}
</div></code></pre>
<h2 id="draw-the-time-series">Draw the time series</h2>
<p>Now we look at how to draw time series as a histogram.</p>
<p>Here is the HTML (save this in <strong>bombs3.html</strong>):</p>
<pre><code class="language-html"><div><span class="hljs-meta"><!DOCTYPE <span class="hljs-meta-keyword">html</span>></span>
<span class="hljs-tag"><<span class="hljs-name">html</span> <span class="hljs-attr">lang</span>=<span class="hljs-string">"en"</span>></span>
<span class="hljs-tag"><<span class="hljs-name">head</span>></span>
<span class="hljs-tag"><<span class="hljs-name">meta</span> <span class="hljs-attr">charset</span>=<span class="hljs-string">"utf-8"</span>></span>
<span class="hljs-tag"><<span class="hljs-name">style</span>></span><span class="css">
<span class="hljs-selector-class">.axis</span> path,
<span class="hljs-selector-class">.axis</span> line {
fill: none;
stroke: black;
shape-rendering: crispEdges;
}
<span class="hljs-selector-class">.bar</span> {
fill: steelblue;
shape-rendering: crispEdges;
}
<span class="hljs-selector-class">.axis</span> text {
<span class="hljs-attribute">font-family</span>: sans-serif;
<span class="hljs-attribute">font-size</span>: <span class="hljs-number">11px</span>;
}
<span class="hljs-selector-class">.x</span><span class="hljs-selector-class">.axis</span> path {
<span class="hljs-attribute">display</span>: none;
}
</span><span class="hljs-tag"></<span class="hljs-name">style</span>></span>
<span class="hljs-tag"><<span class="hljs-name">title</span>></span>D3 Time Series<span class="hljs-tag"></<span class="hljs-name">title</span>></span>
<span class="hljs-tag"><<span class="hljs-name">script</span> <span class="hljs-attr">src</span>=<span class="hljs-string">"https://d3js.org/d3.v7.min.js"</span>></span><span class="hljs-tag"></<span class="hljs-name">script</span>></span>
<span class="hljs-tag"></<span class="hljs-name">head</span>></span>
<span class="hljs-tag"><<span class="hljs-name">body</span>></span>
<span class="hljs-tag"><<span class="hljs-name">h2</span>></span>Time series<span class="hljs-tag"></<span class="hljs-name">h2</span>></span>
<span class="hljs-tag"><<span class="hljs-name">div</span> <span class="hljs-attr">id</span>=<span class="hljs-string">"timehisto"</span>></span><span class="hljs-tag"></<span class="hljs-name">div</span>></span>
<span class="hljs-tag"><<span class="hljs-name">script</span> <span class="hljs-attr">src</span>=<span class="hljs-string">"bombs3.js"</span> <span class="hljs-attr">type</span>=<span class="hljs-string">"text/javascript"</span>></span><span class="hljs-tag"></<span class="hljs-name">script</span>></span>
<span class="hljs-tag"><<span class="hljs-name">div</span> <span class="hljs-attr">id</span>=<span class="hljs-string">"debug"</span>></span><span class="hljs-tag"></<span class="hljs-name">div</span>></span>
<span class="hljs-tag"></<span class="hljs-name">body</span>></span>
<span class="hljs-tag"></<span class="hljs-name">html</span>></span>
</div></code></pre>
<p>And the javascript code is below (saved in <strong>bombs3.js</strong>):</p>
<pre><code class="language-js"><div><span class="hljs-keyword">var</span> bombs_data;
<span class="hljs-keyword">var</span> svg;
<span class="hljs-keyword">var</span> rects;
<span class="hljs-keyword">var</span> parseTime = d3.timeParse(<span class="hljs-string">"%B %d, %Y %I:%M %Z"</span>);
d3.tsv(<span class="hljs-string">"bombs.tsv"</span>).then(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">data</span>) </span>{
data.forEach(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d, i</span>) </span>{
d.id = i;
d.order = +d[<span class="hljs-string">"order"</span>];
d.lng = +d.lng;
d.lat = +d.lat;
d.type = (d.type==<span class="hljs-string">"-"</span>?<span class="hljs-string">"Other"</span>:d.type);
d.time = parseTime(<span class="hljs-string">"September 7, 1940 "</span> + d.time + <span class="hljs-string">" -0400"</span>);
});
bombs_data = data;
make_timechart();
});
<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">make_timechart</span>(<span class="hljs-params"></span>) </span>{
<span class="hljs-keyword">var</span> total_w = <span class="hljs-number">500</span>;
<span class="hljs-keyword">var</span> total_h = <span class="hljs-number">200</span>;
<span class="hljs-keyword">var</span> margin = {<span class="hljs-attr">top</span>: <span class="hljs-number">15</span>, <span class="hljs-attr">right</span>: <span class="hljs-number">20</span>, <span class="hljs-attr">bottom</span>: <span class="hljs-number">50</span>, <span class="hljs-attr">left</span>: <span class="hljs-number">30</span>};
<span class="hljs-keyword">var</span> w = total_w - margin.left - margin.right;
<span class="hljs-keyword">var</span> h = total_h - margin.top - margin.bottom;
<span class="hljs-keyword">var</span> formatTime = d3.timeFormat(<span class="hljs-string">"%H"</span>);
<span class="hljs-keyword">var</span> hourExtent = d3.extent(bombs_data, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> d.time; });
<span class="hljs-comment">// one bin per hour, for 24 hours in the day</span>
<span class="hljs-keyword">var</span> hourBins = d3.timeHours(d3.timeHour.offset(hourExtent[<span class="hljs-number">0</span>],-<span class="hljs-number">1</span>),
d3.timeHour.offset(hourExtent[<span class="hljs-number">1</span>],<span class="hljs-number">1</span>));
<span class="hljs-built_in">console</span>.log(hourBins);
<span class="hljs-comment">// a function to bin the data</span>
<span class="hljs-keyword">var</span> binByHour = d3.histogram()
.value(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> d.time; })
.thresholds(hourBins);
<span class="hljs-comment">// construct the histogram bins from the data</span>
<span class="hljs-keyword">var</span> histData = binByHour(bombs_data);
<span class="hljs-built_in">console</span>.log(<span class="hljs-built_in">Object</span>.keys(histData));
<span class="hljs-built_in">console</span>.log(histData);
<span class="hljs-keyword">var</span> svg = d3.select(<span class="hljs-string">"#timehisto"</span>)
.append(<span class="hljs-string">"svg"</span>)
.attr(<span class="hljs-string">"width"</span>, w + margin.left + margin.right)
.attr(<span class="hljs-string">"height"</span>, h + margin.top + margin.bottom)
.append(<span class="hljs-string">"g"</span>)
.attr(<span class="hljs-string">"transform"</span>, <span class="hljs-string">"translate("</span> + margin.left + <span class="hljs-string">","</span> + margin.top + <span class="hljs-string">")"</span>);
<span class="hljs-keyword">var</span> x = d3.scaleTime().range([<span class="hljs-number">0</span>, w]);
x.domain(d3.extent(hourBins));
<span class="hljs-keyword">var</span> xAxis = d3.axisBottom().scale(x)
.tickFormat(formatTime);
<span class="hljs-keyword">var</span> y = d3.scaleLinear().range([h, <span class="hljs-number">0</span>]);
y.domain([<span class="hljs-number">0</span>, d3.max(histData, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> d.length; })]);
<span class="hljs-keyword">var</span> yAxis = d3.axisLeft().scale(y).ticks(<span class="hljs-number">6</span>);
rects = svg.selectAll(<span class="hljs-string">"rect"</span>)
.data(histData)
.enter()
.append(<span class="hljs-string">"rect"</span>)
.attr(<span class="hljs-string">"class"</span>, <span class="hljs-string">"bar"</span>)
.attr(<span class="hljs-string">"x"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> x(d.x0); })
.attr(<span class="hljs-string">"transform"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> <span class="hljs-string">"translate("</span> + <span class="hljs-number">0</span> + <span class="hljs-string">","</span> + y(d.length) + <span class="hljs-string">")"</span>; }) <span class="hljs-comment">// move them down, otherwise will be hanging</span>
.attr(<span class="hljs-string">"width"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> x(d.x1) - x(d.x0) -<span class="hljs-number">1</span> ; })
.attr(<span class="hljs-string">"height"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> h - y(d.length); })
rects.on(<span class="hljs-string">"mouseover"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">e, d</span>) </span>{ <span class="hljs-comment">// event, datum</span>
d3.select(<span class="hljs-built_in">this</span>).style(<span class="hljs-string">"fill"</span>, <span class="hljs-string">"red"</span>);
d3.select(<span class="hljs-string">"#debug"</span>).html(<span class="hljs-string">"Over: "</span> + d.length + <span class="hljs-string">" "</span> + d + <span class="hljs-string">"; event="</span> + e + <span class="hljs-string">". End."</span>);
})
.on(<span class="hljs-string">"mouseout"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">e, d</span>) </span>{
d3.select(<span class="hljs-built_in">this</span>).style(<span class="hljs-string">"fill"</span>, <span class="hljs-string">"steelblue"</span>);
d3.select(<span class="hljs-string">"#debug"</span>).html(<span class="hljs-string">"Out: d.length="</span> + d.length + <span class="hljs-string">", d "</span> + d + <span class="hljs-string">"; event="</span> + e);
});
svg.append(<span class="hljs-string">"g"</span>)
.attr(<span class="hljs-string">"class"</span>, <span class="hljs-string">"x axis"</span>)
.attr(<span class="hljs-string">"transform"</span>, <span class="hljs-string">"translate(0,"</span> + h + <span class="hljs-string">")"</span>)
.call(xAxis);
svg.append(<span class="hljs-string">"g"</span>)
.attr(<span class="hljs-string">"class"</span>, <span class="hljs-string">"y axis"</span>)
.call(yAxis)
.append(<span class="hljs-string">"text"</span>)
.attr(<span class="hljs-string">"transform"</span>, <span class="hljs-string">"rotate(-90)"</span>)
.attr(<span class="hljs-string">"y"</span>, <span class="hljs-number">6</span>)
.attr(<span class="hljs-string">"dy"</span>, <span class="hljs-string">".71em"</span>)
.style(<span class="hljs-string">"text-anchor"</span>, <span class="hljs-string">"end"</span>)
.text(<span class="hljs-string">"Number of Bombs"</span>);
}
</div></code></pre>
<h2 id="linking-space-and-time">Linking space and time</h2>
<p>Finally we will link bombs on the map and the bars on the histogram.</p>
<pre><code class="language-html"><div><span class="hljs-meta"><!DOCTYPE <span class="hljs-meta-keyword">html</span>></span>
<span class="hljs-tag"><<span class="hljs-name">html</span> <span class="hljs-attr">lang</span>=<span class="hljs-string">"en"</span>></span>
<span class="hljs-tag"><<span class="hljs-name">head</span>></span>
<span class="hljs-tag"><<span class="hljs-name">meta</span> <span class="hljs-attr">charset</span>=<span class="hljs-string">"utf-8"</span>></span>
<span class="hljs-tag"><<span class="hljs-name">style</span>></span><span class="css">
<span class="hljs-selector-id">#map</span> { <span class="hljs-attribute">height</span>: <span class="hljs-number">350px</span>; }
<span class="hljs-selector-class">.axis</span> path,
<span class="hljs-selector-class">.axis</span> line {
fill: none;
stroke: black;
shape-rendering: crispEdges;
}
<span class="hljs-selector-class">.bar</span> {
shape-rendering: crispEdges;
}
<span class="hljs-selector-class">.axis</span> text {
<span class="hljs-attribute">font-family</span>: sans-serif;
<span class="hljs-attribute">font-size</span>: <span class="hljs-number">11px</span>;
}
<span class="hljs-selector-class">.x</span><span class="hljs-selector-class">.axis</span> path {
<span class="hljs-attribute">display</span>: none;
}
</span><span class="hljs-tag"></<span class="hljs-name">style</span>></span>
<span class="hljs-tag"><<span class="hljs-name">title</span>></span>D3 Test<span class="hljs-tag"></<span class="hljs-name">title</span>></span>
<span class="hljs-tag"><<span class="hljs-name">link</span> <span class="hljs-attr">rel</span>=<span class="hljs-string">"stylesheet"</span> <span class="hljs-attr">href</span>=<span class="hljs-string">"https://unpkg.com/leaflet@1.8.0/dist/leaflet.css"</span>
<span class="hljs-attr">integrity</span>=<span class="hljs-string">"sha512-hoalWLoI8r4UszCkZ5kL8vayOGVae1oxXe/2A4AO6J9+580uKHDO3JdHb7NzwwzK5xr/Fs0W40kiNHxM9vyTtQ=="</span>
<span class="hljs-attr">crossorigin</span>=<span class="hljs-string">""</span>/></span>
<span class="hljs-comment"><!-- Make sure you put this AFTER Leaflet's CSS --></span>
<span class="hljs-tag"><<span class="hljs-name">script</span> <span class="hljs-attr">src</span>=<span class="hljs-string">"https://unpkg.com/leaflet@1.8.0/dist/leaflet.js"</span>
<span class="hljs-attr">integrity</span>=<span class="hljs-string">"sha512-BB3hKbKWOc9Ez/TAwyWxNXeoV9c1v6FIeYiBieIWkpLjauysF18NzgR1MBNBXf8/KABdlkX68nAhlwcDFLGPCQ=="</span>
<span class="hljs-attr">crossorigin</span>=<span class="hljs-string">""</span>></span><span class="hljs-tag"></<span class="hljs-name">script</span>></span>
<span class="hljs-tag"><<span class="hljs-name">script</span> <span class="hljs-attr">src</span>=<span class="hljs-string">"https://d3js.org/d3.v7.min.js"</span>></span><span class="hljs-tag"></<span class="hljs-name">script</span>></span>
<span class="hljs-comment"><!-- <link rel="stylesheet" href="https://unpkg.com/leaflet@1.0.0-rc.3/dist/leaflet.css" />
<script src="https://unpkg.com/leaflet@1.0.0-rc.3/dist/leaflet.js"></script>
<script src="http://d3js.org/d3.v3.min.js"></script> --></span>
<span class="hljs-tag"></<span class="hljs-name">head</span>></span>
<span class="hljs-tag"><<span class="hljs-name">body</span>></span>
<span class="hljs-tag"><<span class="hljs-name">h2</span>></span>24 hours of Blitz Sept 7th 1940: Map and Time<span class="hljs-tag"></<span class="hljs-name">h2</span>></span>
<span class="hljs-tag"><<span class="hljs-name">div</span> <span class="hljs-attr">id</span>=<span class="hljs-string">"map"</span>></span><span class="hljs-tag"></<span class="hljs-name">div</span>></span>
<span class="hljs-tag"><<span class="hljs-name">div</span> <span class="hljs-attr">id</span>=<span class="hljs-string">"timehisto"</span>></span><span class="hljs-tag"></<span class="hljs-name">div</span>></span>
<span class="hljs-tag"><<span class="hljs-name">script</span> <span class="hljs-attr">src</span>=<span class="hljs-string">"bombs4.js"</span> <span class="hljs-attr">type</span>=<span class="hljs-string">"text/javascript"</span>></span><span class="hljs-tag"></<span class="hljs-name">script</span>></span>
<span class="hljs-tag"><<span class="hljs-name">div</span> <span class="hljs-attr">id</span>=<span class="hljs-string">"debug"</span>></span><span class="hljs-tag"></<span class="hljs-name">div</span>></span>
<span class="hljs-tag"></<span class="hljs-name">body</span>></span>
<span class="hljs-tag"></<span class="hljs-name">html</span>></span>
</div></code></pre>
<p>And here is the JS:</p>
<pre><code class="language-js"><div>
<span class="hljs-keyword">var</span> bombs_data;
<span class="hljs-keyword">var</span> bombs_geojson;
<span class="hljs-keyword">var</span> hourBins;
<span class="hljs-keyword">var</span> layer_geojsons = {};
<span class="hljs-keyword">var</span> svg;
<span class="hljs-keyword">var</span> rects;
<span class="hljs-keyword">var</span> map;
<span class="hljs-keyword">var</span> bombs_layer;
<span class="hljs-keyword">var</span> histData;
<span class="hljs-keyword">var</span> ll_ids;
<span class="hljs-keyword">var</span> parseTime = d3.timeParse(<span class="hljs-string">"%B %d, %Y %I:%M %Z"</span>);
<span class="hljs-keyword">var</span> bisectTime = d3.bisector(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> d; }).left;
<span class="hljs-keyword">var</span> default_bombs_style = {
<span class="hljs-attr">color</span>: <span class="hljs-string">"none"</span>,
<span class="hljs-attr">radius</span>: <span class="hljs-number">6</span>,
<span class="hljs-attr">fillColor</span>: <span class="hljs-string">"red"</span>,
<span class="hljs-attr">opacity</span>: <span class="hljs-number">1</span>,
<span class="hljs-attr">fillOpacity</span>: <span class="hljs-number">0.3</span>,
<span class="hljs-attr">weight</span>: <span class="hljs-number">0</span>
};
<span class="hljs-keyword">var</span> highlight_bombs_style = {
<span class="hljs-attr">fillColor</span>: <span class="hljs-string">'yellow'</span>,
<span class="hljs-attr">color</span>: <span class="hljs-string">"grey"</span>,
<span class="hljs-attr">fillOpacity</span>: <span class="hljs-number">0.8</span>,
<span class="hljs-attr">weight</span>: <span class="hljs-number">2</span>
}
d3.tsv(<span class="hljs-string">"bombs.tsv"</span>).then(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">data</span>) </span>{
bombs_geojson = {
<span class="hljs-string">"type"</span>: <span class="hljs-string">"FeatureCollection"</span>,
<span class="hljs-string">"features"</span>: []
};
data.forEach(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d, i</span>) </span>{
d.id = i;
d.order = +d[<span class="hljs-string">"order"</span>];
d.lng = +d.lng;
d.lat = +d.lat;
d.type = (d.type==<span class="hljs-string">"-"</span>?<span class="hljs-string">"Other"</span>:d.type);
d.time = parseTime(<span class="hljs-string">"September 7, 1940 "</span> + d.time + <span class="hljs-string">" -0400"</span>);
bombs_geojson.features[i] = {
<span class="hljs-string">"type"</span>: <span class="hljs-string">"Feature"</span>,
<span class="hljs-string">"geometry"</span>: {
<span class="hljs-string">"type"</span>: <span class="hljs-string">"Point"</span>,
<span class="hljs-string">"coordinates"</span>: [d.lng, d.lat]
},
<span class="hljs-string">"properties"</span>: {
<span class="hljs-string">"id"</span>: i
}
};
});
bombs_data = data;
make_timechart();
make_maps();
});
<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">make_timechart</span>(<span class="hljs-params"></span>) </span>{
<span class="hljs-keyword">var</span> total_w = <span class="hljs-number">500</span>;
<span class="hljs-keyword">var</span> total_h = <span class="hljs-number">200</span>;
<span class="hljs-keyword">var</span> margin = {<span class="hljs-attr">top</span>: <span class="hljs-number">15</span>, <span class="hljs-attr">right</span>: <span class="hljs-number">20</span>, <span class="hljs-attr">bottom</span>: <span class="hljs-number">50</span>, <span class="hljs-attr">left</span>: <span class="hljs-number">30</span>};
<span class="hljs-keyword">var</span> w = total_w - margin.left - margin.right;
<span class="hljs-keyword">var</span> h = total_h - margin.top - margin.bottom;
<span class="hljs-keyword">var</span> formatTime = d3.timeFormat(<span class="hljs-string">"%H"</span>);
<span class="hljs-keyword">var</span> hourExtent = d3.extent(bombs_data, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> d.time; });
<span class="hljs-comment">// one bin per hour, for 24 hours in the day</span>
hourBins = d3.timeHours(d3.timeHour.offset(hourExtent[<span class="hljs-number">0</span>],-<span class="hljs-number">1</span>),
d3.timeHour.offset(hourExtent[<span class="hljs-number">1</span>],<span class="hljs-number">1</span>));
<span class="hljs-built_in">console</span>.log(hourBins);
<span class="hljs-comment">// a function to bin the data</span>
<span class="hljs-keyword">var</span> binByHour = d3.histogram()
.value(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> d.time; })
.thresholds(hourBins);
<span class="hljs-comment">// construct the histogram bins from the data</span>
histData = binByHour(bombs_data);
<span class="hljs-built_in">console</span>.log(<span class="hljs-built_in">Object</span>.keys(histData));
<span class="hljs-built_in">console</span>.log(histData);
<span class="hljs-keyword">var</span> svg = d3.select(<span class="hljs-string">"#timehisto"</span>)
.append(<span class="hljs-string">"svg"</span>)
.attr(<span class="hljs-string">"width"</span>, w + margin.left + margin.right)
.attr(<span class="hljs-string">"height"</span>, h + margin.top + margin.bottom)
.append(<span class="hljs-string">"g"</span>)
.attr(<span class="hljs-string">"transform"</span>, <span class="hljs-string">"translate("</span> + margin.left + <span class="hljs-string">","</span> + margin.top + <span class="hljs-string">")"</span>);
<span class="hljs-keyword">var</span> x = d3.scaleTime().range([<span class="hljs-number">0</span>, w]);
x.domain(d3.extent(hourBins));
<span class="hljs-keyword">var</span> xAxis = d3.axisBottom().scale(x)
.tickFormat(formatTime);
<span class="hljs-keyword">var</span> y = d3.scaleLinear().range([h, <span class="hljs-number">0</span>]);
y.domain([<span class="hljs-number">0</span>, d3.max(histData, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> d.length; })]);
<span class="hljs-keyword">var</span> yAxis = d3.axisLeft().scale(y).ticks(<span class="hljs-number">6</span>);
rects = svg.selectAll(<span class="hljs-string">"rect"</span>)
.data(histData)
.enter()
.append(<span class="hljs-string">"rect"</span>)
.attr(<span class="hljs-string">"fill"</span>, default_bombs_style[<span class="hljs-string">"fillColor"</span>])
.attr(<span class="hljs-string">"class"</span>, <span class="hljs-string">"bar"</span>)
.attr(<span class="hljs-string">"x"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> x(d.x0); })
.attr(<span class="hljs-string">"transform"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> <span class="hljs-string">"translate("</span> + <span class="hljs-number">0</span> + <span class="hljs-string">","</span> + y(d.length) + <span class="hljs-string">")"</span>; }) <span class="hljs-comment">// move them down, otherwise will be hanging</span>
.attr(<span class="hljs-string">"width"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> x(d.x1) - x(d.x0) -<span class="hljs-number">1</span> ; })
.attr(<span class="hljs-string">"height"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d</span>) </span>{ <span class="hljs-keyword">return</span> h - y(d.length); })
rects.on(<span class="hljs-string">"mouseover"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">e, d</span>) </span>{ <span class="hljs-comment">// event, datum</span>
d3.select(<span class="hljs-built_in">this</span>).style(<span class="hljs-string">"fill"</span>, highlight_bombs_style[<span class="hljs-string">"fillColor"</span>]);
d3.select(<span class="hljs-string">"#debug"</span>).html(<span class="hljs-string">"Over: "</span> + d.length + <span class="hljs-string">" "</span> + d.x0 + <span class="hljs-string">"; event="</span> + e + <span class="hljs-string">". End."</span>);
<span class="hljs-comment">// get the index ix</span>
ix = bisectTime(hourBins, d.x0);
ll_ids[ix].forEach(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">dd</span>) </span>{
l = bombs_layer.getLayer(dd);
l.setStyle(highlight_bombs_style);
<span class="hljs-keyword">if</span> (!L.Browser.ie && !L.Browser.opera) {
l.bringToFront();
}
})
})
.on(<span class="hljs-string">"mouseout"</span>, <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">e, d</span>) </span>{
d3.select(<span class="hljs-built_in">this</span>).style(<span class="hljs-string">"fill"</span>, default_bombs_style[<span class="hljs-string">"fillColor"</span>]);
d3.select(<span class="hljs-string">"#debug"</span>).html(<span class="hljs-string">"Out: d.length="</span> + d.length + <span class="hljs-string">", d "</span> + d + <span class="hljs-string">"; event="</span> + e);
ix = bisectTime(hourBins, d.x0);
ll_ids[ix].forEach(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">dd</span>) </span>{
bombs_layer.resetStyle(bombs_layer.getLayer(dd));})
});
svg.append(<span class="hljs-string">"g"</span>)
.attr(<span class="hljs-string">"class"</span>, <span class="hljs-string">"x axis"</span>)
.attr(<span class="hljs-string">"transform"</span>, <span class="hljs-string">"translate(0,"</span> + h + <span class="hljs-string">")"</span>)
.call(xAxis);
svg.append(<span class="hljs-string">"g"</span>)
.attr(<span class="hljs-string">"class"</span>, <span class="hljs-string">"y axis"</span>)
.call(yAxis)
.append(<span class="hljs-string">"text"</span>)
.attr(<span class="hljs-string">"transform"</span>, <span class="hljs-string">"rotate(-90)"</span>)
.attr(<span class="hljs-string">"y"</span>, <span class="hljs-number">6</span>)
.attr(<span class="hljs-string">"dy"</span>, <span class="hljs-string">".71em"</span>)
.style(<span class="hljs-string">"text-anchor"</span>, <span class="hljs-string">"end"</span>)
.text(<span class="hljs-string">"Number of Bombs"</span>);
}
<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">onEachBombsFeature</span>(<span class="hljs-params">feature, layer</span>) </span>{
<span class="hljs-comment">// find the bin that contains this point and push the id to ll_ids</span>
id = L.stamp(layer);
i = bisectTime(hourBins, bombs_data[feature.properties.id].time) - <span class="hljs-number">1</span>; <span class="hljs-comment">// find the right bin</span>
ll_ids[i].push(id);
layer.on({
<span class="hljs-attr">mouseover</span>: <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">e</span>) </span>{
<span class="hljs-keyword">var</span> layer = e.target;
feature = layer.feature;
feature_id = feature.properties.id;
<span class="hljs-keyword">var</span> t = bombs_data[feature_id].time;
hist_index = bisectTime(hourBins, t) - <span class="hljs-number">1</span>;
ll_ids[hist_index].forEach(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">dd</span>) </span>{
l = bombs_layer.getLayer(dd);
l.setStyle(highlight_bombs_style);
<span class="hljs-keyword">if</span> (!L.Browser.ie && !L.Browser.opera) {
l.bringToFront();
}
})
<span class="hljs-comment">// highlight more on self</span>
layer.setStyle({
<span class="hljs-attr">radius</span>: default_bombs_style[<span class="hljs-string">"radius"</span>]+<span class="hljs-number">3</span>
});
<span class="hljs-keyword">if</span> (!L.Browser.ie && !L.Browser.opera) {
layer.bringToFront();
}
d3.select(<span class="hljs-string">"#debug"</span>).html(t + <span class="hljs-string">": "</span> + bombs_data[feature_id].details);
d3.selectAll(<span class="hljs-string">"rect"</span>)
.filter(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d, i</span>) </span>{
hist_index = bisectTime(hourBins, t) - <span class="hljs-number">1</span>;
<span class="hljs-keyword">return</span> (hist_index == i); })
.style(<span class="hljs-string">"fill"</span>, highlight_bombs_style[<span class="hljs-string">"fillColor"</span>]);
},
<span class="hljs-attr">mouseout</span>: <span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">e</span>) </span>{
<span class="hljs-comment">// bombs_layer.resetStyle(e.target);</span>
<span class="hljs-keyword">var</span> t = bombs_data[feature_id].time;
hist_index = bisectTime(hourBins, t) - <span class="hljs-number">1</span>;
ll_ids[hist_index].forEach(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">dd</span>) </span>{
bombs_layer.resetStyle(bombs_layer.getLayer(dd));})
d3.selectAll(<span class="hljs-string">"rect"</span>)
.filter(<span class="hljs-function"><span class="hljs-keyword">function</span>(<span class="hljs-params">d, i</span>) </span>{
hist_index = bisectTime(hourBins, t) - <span class="hljs-number">1</span>;
<span class="hljs-keyword">return</span> (hist_index == i); })
.style(<span class="hljs-string">"fill"</span>, default_bombs_style[<span class="hljs-string">"fillColor"</span>]);
}
})
}
<span class="hljs-function"><span class="hljs-keyword">function</span> <span class="hljs-title">make_maps</span>(<span class="hljs-params"></span>) </span>{
map = L.map(<span class="hljs-string">'map'</span>);
map.setView([<span class="hljs-number">51.5</span>, -<span class="hljs-number">0.1</span>], <span class="hljs-number">10</span>);
<span class="hljs-comment">// create an OpenStreetMap tile layer</span>
<span class="hljs-keyword">var</span> osmMapnik = L.tileLayer(<span class="hljs-string">'http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png'</span>, {
<span class="hljs-attr">attribution</span>: <span class="hljs-string">'&copy; <a href="http://osm.org/copyright">OpenStreetMap</a>contributors'</span>
});
<span class="hljs-comment">// create another layer using the cartodb service</span>
<span class="hljs-keyword">var</span> cartoLight = L.tileLayer(<span class="hljs-string">"https://cartodb-basemaps-{s}.global.ssl.fastly.net/light_all/{z}/{x}/{y}.png"</span>, {
<span class="hljs-attr">attribution</span>: <span class="hljs-string">'&copy; <a href="http://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors, &copy; <a href="https://cartodb.com/attributions">CartoDB</a>'</span>
});
<span class="hljs-keyword">var</span> baseMaps = {
<span class="hljs-string">"Street map light"</span>: cartoLight,
<span class="hljs-string">"OpenStreetMap"</span>: osmMapnik
};
<span class="hljs-keyword">var</span> layersControl = <span class="hljs-keyword">new</span> L.Control.Layers(baseMaps, <span class="hljs-literal">null</span>, {<span class="hljs-attr">collapsed</span>: <span class="hljs-literal">true</span>, <span class="hljs-attr">position</span>: <span class="hljs-string">'bottomleft'</span>});
map.addControl(layersControl);
map.addLayer(cartoLight, <span class="hljs-literal">true</span>);
ll_ids = []; <span class="hljs-comment">// leaflet layer ids, very important</span>
<span class="hljs-keyword">for</span> (i=<span class="hljs-number">0</span>; i<histData.length; i++)
ll_ids[i] = [];
bombs_layer = L.geoJson(bombs_geojson, {
<span class="hljs-attr">pointToLayer</span>: <span class="hljs-function"><span class="hljs-keyword">function</span> (<span class="hljs-params">feature, latlng</span>) </span>{
<span class="hljs-keyword">return</span> L.circleMarker(latlng);
},
<span class="hljs-attr">style</span>: <span class="hljs-function"><span class="hljs-keyword">function</span> (<span class="hljs-params">feature</span>) </span>{
<span class="hljs-keyword">return</span> default_bombs_style;
},
<span class="hljs-attr">onEachFeature</span>: onEachBombsFeature
});
bombs_layer.addTo(map);
layersControl.addOverlay(bombs_layer, <span class="hljs-string">"Bombs"</span>);
}
</div></code></pre>
<p>When we are done, we should see a webpage like this:</p>
<p><img src="screenshot1.png" alt=""></p>
<h2 id="discussion">Discussion</h2>
<p>What are the ways to improve the visualization we have explored so far?</p>
</body>
</html>