bewest · December 17, 2012 08:38 · Oct 12, 2012 · Jun 28, 2012 · Jun 28, 2012 · Jun 28, 2012
diff --git a/thumbnail.png b/thumbnail.png
diff --git a/README.md b/README.md
@@ -1 +1,3 @@
-An example of the [d3.horizon](https://github.com/d3/d3-plugins/tree/master/horizon) plugin.
+Horizon charts combine position and color to reduce vertical space. Start with a standard area chart, then **mirror** negative values (in blue) or **offset** them vertically. Click the **+ button** above to increase the number of bands, turning the area into a horizon.
+
+Implemented with the [d3.horizon](https://github.com/d3/d3-plugins/tree/master/horizon) plugin.
diff --git a/index.html b/index.html
@@ -1,7 +1,7 @@
 <style>
 
 body {
-  font: 10px sans-serif;
+  font-family: sans-serif;
 }
 
 svg {
@@ -11,15 +11,13 @@
 
 #horizon-controls {
   position: absolute;
-  width: 960px;
-  font-size: 16px;
-  margin-bottom: 6px;
+  width: 940px;
+  padding: 10px;
   z-index: 1;
 }
 
 #horizon-bands {
-  position: absolute;
-  right: 0;
+  float: right;
 }
 
 </style>

diff --git a/index.html b/index.html
@@ -1,10 +1,20 @@
 <style>
 
+body {
+  font: 10px sans-serif;
+}
+
+svg {
+  position: absolute;
+  top: 0;
+}
+
 #horizon-controls {
-  position: relative;
-  width: 100%;
+  position: absolute;
+  width: 960px;
   font-size: 16px;
   margin-bottom: 6px;
+  z-index: 1;
 }
 
 #horizon-bands {
@@ -19,12 +29,12 @@
   <span id="horizon-bands"><span id="horizon-bands-value">1</span> <button class="first">&#x2212;</button><button class="last">+</button></span>
 </div>
 <div id="horizon-chart"></div>
-<script src="http://d3js.org/d3.v2.min.js?2.9.5"></script>
+<script src="http://d3js.org/d3.v2.js?2.9.5"></script>
 <script src="horizon.js?0.0.1"></script>
 <script>
 
 var width = 960,
-    height = 360;
+    height = 500;
 
 var chart = d3.horizon()
     .width(width)

diff --git a/index.html b/index.html
@@ -19,6 +19,7 @@
   <span id="horizon-bands"><span id="horizon-bands-value">1</span> <button class="first">&#x2212;</button><button class="last">+</button></span>
 </div>
 <div id="horizon-chart"></div>
+<script src="http://d3js.org/d3.v2.min.js?2.9.5"></script>
 <script src="horizon.js?0.0.1"></script>
 <script>
 

diff --git a/README.md b/README.md
@@ -1 +1 @@
-Note: this uses the d3.chart module, which is deprecated. I need to rewrite the horizon component!
+An example of the [d3.horizon](https://github.com/d3/d3-plugins/tree/master/horizon) plugin.
diff --git a/horizon.js b/horizon.js
@@ -0,0 +1,192 @@
+(function() {
+  d3.horizon = function() {
+    var bands = 1, // between 1 and 5, typically
+        mode = "offset", // or mirror
+        interpolate = "linear", // or basis, monotone, step-before, etc.
+        x = d3_horizonX,
+        y = d3_horizonY,
+        w = 960,
+        h = 40,
+        duration = 0;
+
+    var color = d3.scale.linear()
+        .domain([-1, 0, 0, 1])
+        .range(["#08519c", "#bdd7e7", "#bae4b3", "#006d2c"]);
+
+    // For each small multiple…
+    function horizon(g) {
+      g.each(function(d, i) {
+        var g = d3.select(this),
+            n = 2 * bands + 1,
+            xMin = Infinity,
+            xMax = -Infinity,
+            yMax = -Infinity,
+            x0, // old x-scale
+            y0, // old y-scale
+            id; // unique id for paths
+
+        // Compute x- and y-values along with extents.
+        var data = d.map(function(d, i) {
+          var xv = x.call(this, d, i),
+              yv = y.call(this, d, i);
+          if (xv < xMin) xMin = xv;
+          if (xv > xMax) xMax = xv;
+          if (-yv > yMax) yMax = -yv;
+          if (yv > yMax) yMax = yv;
+          return [xv, yv];
+        });
+
+        // Compute the new x- and y-scales, and transform.
+        var x1 = d3.scale.linear().domain([xMin, xMax]).range([0, w]),
+            y1 = d3.scale.linear().domain([0, yMax]).range([0, h * bands]),
+            t1 = d3_horizonTransform(bands, h, mode);
+
+        // Retrieve the old scales, if this is an update.
+        if (this.__chart__) {
+          x0 = this.__chart__.x;
+          y0 = this.__chart__.y;
+          t0 = this.__chart__.t;
+          id = this.__chart__.id;
+        } else {
+          x0 = x1.copy();
+          y0 = y1.copy();
+          t0 = t1;
+          id = ++d3_horizonId;
+        }
+
+        // We'll use a defs to store the area path and the clip path.
+        var defs = g.selectAll("defs")
+            .data([null]);
+
+        // The clip path is a simple rect.
+        defs.enter().append("defs").append("clipPath")
+            .attr("id", "d3_horizon_clip" + id)
+          .append("rect")
+            .attr("width", w)
+            .attr("height", h);
+
+        defs.select("rect").transition()
+            .duration(duration)
+            .attr("width", w)
+            .attr("height", h);
+
+        // We'll use a container to clip all horizon layers at once.
+        g.selectAll("g")
+            .data([null])
+          .enter().append("g")
+            .attr("clip-path", "url(#d3_horizon_clip" + id + ")");
+
+        // Instantiate each copy of the path with different transforms.
+        var path = g.select("g").selectAll("path")
+            .data(d3.range(-1, -bands - 1, -1).concat(d3.range(1, bands + 1)), Number);
+
+        var d0 = d3_horizonArea
+            .interpolate(interpolate)
+            .x(function(d) { return x0(d[0]); })
+            .y0(h * bands)
+            .y1(function(d) { return h * bands - y0(d[1]); })
+            (data);
+
+        var d1 = d3_horizonArea
+            .x(function(d) { return x1(d[0]); })
+            .y1(function(d) { return h * bands - y1(d[1]); })
+            (data);
+
+        path.enter().append("path")
+            .style("fill", color)
+            .attr("transform", t0)
+            .attr("d", d0);
+
+        path.transition()
+            .duration(duration)
+            .style("fill", color)
+            .attr("transform", t1)
+            .attr("d", d1);
+
+        path.exit().transition()
+            .duration(duration)
+            .attr("transform", t1)
+            .attr("d", d1)
+            .remove();
+
+        // Stash the new scales.
+        this.__chart__ = {x: x1, y: y1, t: t1, id: id};
+      });
+      d3.timer.flush();
+    }
+
+    horizon.duration = function(x) {
+      if (!arguments.length) return duration;
+      duration = +x;
+      return horizon;
+    };
+
+    horizon.bands = function(x) {
+      if (!arguments.length) return bands;
+      bands = +x;
+      color.domain([-bands, 0, 0, bands]);
+      return horizon;
+    };
+
+    horizon.mode = function(x) {
+      if (!arguments.length) return mode;
+      mode = x + "";
+      return horizon;
+    };
+
+    horizon.colors = function(x) {
+      if (!arguments.length) return color.range();
+      color.range(x);
+      return horizon;
+    };
+
+    horizon.interpolate = function(x) {
+      if (!arguments.length) return interpolate;
+      interpolate = x + "";
+      return horizon;
+    };
+
+    horizon.x = function(z) {
+      if (!arguments.length) return x;
+      x = z;
+      return horizon;
+    };
+
+    horizon.y = function(z) {
+      if (!arguments.length) return y;
+      y = z;
+      return horizon;
+    };
+
+    horizon.width = function(x) {
+      if (!arguments.length) return w;
+      w = +x;
+      return horizon;
+    };
+
+    horizon.height = function(x) {
+      if (!arguments.length) return h;
+      h = +x;
+      return horizon;
+    };
+
+    return horizon;
+  };
+
+  var d3_horizonArea = d3.svg.area(),
+      d3_horizonId = 0;
+
+  function d3_horizonX(d) {
+    return d[0];
+  }
+
+  function d3_horizonY(d) {
+    return d[1];
+  }
+
+  function d3_horizonTransform(bands, h, mode) {
+    return mode == "offset"
+        ? function(d) { return "translate(0," + (d + (d < 0) - bands) * h + ")"; }
+        : function(d) { return (d < 0 ? "scale(1,-1)" : "") + "translate(0," + (d - bands) * h + ")"; };
+  }
+})();
diff --git a/index.html b/index.html
@@ -1,31 +1,40 @@
-<!DOCTYPE html>
-<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
+<style>
 
-<div id="chart"></div>
-
-<div id="controls">
-  <input name="mode" type="radio" value="offset" id="mode-offset" checked><label for="mode-offset"> Offset</label>
-  <input name="mode" type="radio" value="mirror" id="mode-mirror"><label for="mode-mirror"> Mirror</label>
-  <span id="bands"><button class="first">&#x2212;</button><button class="last">+</button></span>
-</div>
-
-<script type="text/javascript" src="http://mbostock.github.com/d3/d3.js?2.7.0"></script>
-<script type="text/javascript" src="http://mbostock.github.com/d3/d3.chart.js?2.7.0"></script>
-<script type="text/javascript">
+#horizon-controls {
+  position: relative;
+  width: 100%;
+  font-size: 16px;
+  margin-bottom: 6px;
+}
 
-var w = 960,
-    h = 80;
+#horizon-bands {
+  position: absolute;
+  right: 0;
+}
 
-var chart = d3.chart.horizon()
-    .width(w)
-    .height(h)
-    .bands(5)
-    .mode("offset")
+</style>
+<div id="horizon-controls">
+  <input name="mode" type="radio" value="mirror" id="horizon-mode-mirror" checked><label for="horizon-mode-mirror"> Mirror</label>
+  <input name="mode" type="radio" value="offset" id="horizon-mode-offset"><label for="horizon-mode-offset"> Offset</label>
+  <span id="horizon-bands"><span id="horizon-bands-value">1</span> <button class="first">&#x2212;</button><button class="last">+</button></span>
+</div>
+<div id="horizon-chart"></div>
+<script src="horizon.js?0.0.1"></script>
+<script>
+
+var width = 960,
+    height = 360;
+
+var chart = d3.horizon()
+    .width(width)
+    .height(height)
+    .bands(1)
+    .mode("mirror")
     .interpolate("basis");
 
-var svg = d3.select("#chart").append("svg")
-    .attr("width", w)
-    .attr("height", h);
+var svg = d3.select("body").append("svg")
+    .attr("width", width)
+    .attr("height", height);
 
 d3.json("unemployment.json", function(data) {
 
@@ -41,27 +50,16 @@
   svg.data([data]).call(chart);
 
   // Enable mode buttons.
-  d3.selectAll("input[name=mode]").on("change", function() {
+  d3.selectAll("#horizon-controls input[name=mode]").on("change", function() {
     svg.call(chart.duration(0).mode(this.value));
   });
 
   // Enable bands buttons.
-  d3.selectAll("#bands button").data([-1, 1]).on("click", function(d) {
-    svg.call(chart.duration(1000).bands(Math.max(1, chart.bands() + d)));
+  d3.selectAll("#horizon-bands button").data([-1, 1]).on("click", function(d) {
+    var n = Math.max(1, chart.bands() + d);
+    d3.select("#horizon-bands-value").text(n);
+    svg.call(chart.duration(1000).bands(n).height(height / n));
   });
 });
 
-</script>
-<style type="text/css">
-
-#controls {
-  position: relative;
-  width: 960px;
-}
-
-#bands {
-  position: absolute;
-  right: 0;
-}
-
-</style>
+</script>
diff --git a/index.html b/index.html
@@ -4,8 +4,8 @@
 <div id="chart"></div>
 
 <div id="controls">
-  <input name="mode" type="radio" id="offset" checked><label for="offset"> Offset</label>
-  <input name="mode" type="radio" id="mirror"><label for="mirror"> Mirror</label>
+  <input name="mode" type="radio" value="offset" id="mode-offset" checked><label for="mode-offset"> Offset</label>
+  <input name="mode" type="radio" value="mirror" id="mode-mirror"><label for="mode-mirror"> Mirror</label>
   <span id="bands"><button class="first">&#x2212;</button><button class="last">+</button></span>
 </div>
 

diff --git a/index.html b/index.html
@@ -4,8 +4,8 @@
 <div id="chart"></div>
 
 <div id="controls">
-  <input name="mode" id="offset" checked><label for="offset"> Offset</label>
-  <input name="mode" id="mirror"><label for="mirror"> Mirror</label>
+  <input name="mode" type="radio" id="offset" checked><label for="offset"> Offset</label>
+  <input name="mode" type="radio" id="mirror"><label for="mirror"> Mirror</label>
   <span id="bands"><button class="first">&#x2212;</button><button class="last">+</button></span>
 </div>
 
@@ -14,7 +14,7 @@
 <script type="text/javascript">
 
 var w = 960,
-    h = 120;
+    h = 80;
 
 var chart = d3.chart.horizon()
     .width(w)

diff --git a/index.html b/index.html
@@ -4,14 +4,9 @@
 <div id="chart"></div>
 
 <div id="controls">
-  <span id="mode">
-    <button class="first active">Offset</button
-    ><button class="last">Mirror</button>
-  </span>
-  <span id="bands">
-    <button class="first">&#x2212;</button
-    ><button class="last">+</button>
-  </span>
+  <input name="mode" id="offset" checked><label for="offset"> Offset</label>
+  <input name="mode" id="mirror"><label for="mirror"> Mirror</label>
+  <span id="bands"><button class="first">&#x2212;</button><button class="last">+</button></span>
 </div>
 
 <script type="text/javascript" src="http://mbostock.github.com/d3/d3.js?2.7.0"></script>
@@ -46,29 +41,19 @@
   svg.data([data]).call(chart);
 
   // Enable mode buttons.
-  d3.selectAll("#mode button")
-      .data(["offset", "mirror"])
-      .on("click", function(m) {
-        svg.call(chart.duration(0).mode(m));
-        d3.selectAll("#mode button")
-            .classed("active", function(d) { return d == m; });
-      });
+  d3.selectAll("input[name=mode]").on("change", function() {
+    svg.call(chart.duration(0).mode(this.value));
+  });
 
   // Enable bands buttons.
-  d3.selectAll("#bands button")
-      .data([-1, 1])
-      .on("click", function bands(db) {
-        svg.call(chart.duration(1000).bands(Math.max(1, chart.bands() + db)));
-      });
+  d3.selectAll("#bands button").data([-1, 1]).on("click", function(d) {
+    svg.call(chart.duration(1000).bands(Math.max(1, chart.bands() + d)));
+  });
 });
 
 </script>
 <style type="text/css">
 
-button.active {
-  background-color: rgb(65,102,133);
-}
-
 #controls {
   position: relative;
   width: 960px;

diff --git a/index.html b/index.html
@@ -65,6 +65,10 @@
 </script>
 <style type="text/css">
 
+button.active {
+  background-color: rgb(65,102,133);
+}
+
 #controls {
   position: relative;
   width: 960px;

diff --git a/index.html b/index.html
@@ -19,7 +19,7 @@
 <script type="text/javascript">
 
 var w = 960,
-    h = 40;
+    h = 120;
 
 var chart = d3.chart.horizon()
     .width(w)

diff --git a/README.md b/README.md
@@ -0,0 +1 @@
+Note: this uses the d3.chart module, which is deprecated. I need to rewrite the horizon component!
diff --git a/index.html b/index.html
@@ -0,0 +1,78 @@
+<!DOCTYPE html>
+<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
+
+<div id="chart"></div>
+
+<div id="controls">
+  <span id="mode">
+    <button class="first active">Offset</button
+    ><button class="last">Mirror</button>
+  </span>
+  <span id="bands">
+    <button class="first">&#x2212;</button
+    ><button class="last">+</button>
+  </span>
+</div>
+
+<script type="text/javascript" src="http://mbostock.github.com/d3/d3.js?2.7.0"></script>
+<script type="text/javascript" src="http://mbostock.github.com/d3/d3.chart.js?2.7.0"></script>
+<script type="text/javascript">
+
+var w = 960,
+    h = 40;
+
+var chart = d3.chart.horizon()
+    .width(w)
+    .height(h)
+    .bands(5)
+    .mode("offset")
+    .interpolate("basis");
+
+var svg = d3.select("#chart").append("svg")
+    .attr("width", w)
+    .attr("height", h);
+
+d3.json("unemployment.json", function(data) {
+
+  // Offset so that positive is above-average and negative is below-average.
+  var mean = data.rate.reduce(function(p, v) { return p + v; }, 0) / data.rate.length;
+
+  // Transpose column values to rows.
+  data = data.rate.map(function(rate, i) {
+    return [Date.UTC(data.year[i], data.month[i] - 1), rate - mean];
+  });
+
+  // Render the chart.
+  svg.data([data]).call(chart);
+
+  // Enable mode buttons.
+  d3.selectAll("#mode button")
+      .data(["offset", "mirror"])
+      .on("click", function(m) {
+        svg.call(chart.duration(0).mode(m));
+        d3.selectAll("#mode button")
+            .classed("active", function(d) { return d == m; });
+      });
+
+  // Enable bands buttons.
+  d3.selectAll("#bands button")
+      .data([-1, 1])
+      .on("click", function bands(db) {
+        svg.call(chart.duration(1000).bands(Math.max(1, chart.bands() + db)));
+      });
+});
+
+</script>
+<style type="text/css">
+
+#controls {
+  position: relative;
+  width: 960px;
+}
+
+#bands {
+  position: absolute;
+  right: 0;
+}
+
+</style>
diff --git a/unemployment.json b/unemployment.json
@@ -0,0 +1 @@
+{"year":[2000,2000,2000,2000,2000,2000,2000,2000,2000,2000,2000,2000,2001,2001,2001,2001,2001,2001,2001,2001,2001,2001,2001,2001,2002,2002,2002,2002,2002,2002,2002,2002,2002,2002,2002,2002,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2006,2006,2006,2006,2006,2006,2006,2006,2006,2006,2006,2006,2007,2007,2007,2007,2007,2007,2007,2007,2007,2007,2007,2007,2008,2008,2008,2008,2008,2008,2008,2008,2008,2008,2008,2008,2009,2009,2009,2009,2009,2009,2009,2009,2009,2009,2009,2009,2010,2010],"month":[1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2],"rate":[4.5,4.4,4.3,3.7,3.8,4.1,4.2,4.1,3.8,3.6,3.7,3.7,4.7,4.6,4.5,4.2,4.1,4.7,4.7,4.9,4.7,5,5.3,5.4,6.3,6.1,6.1,5.7,5.5,6,5.9,5.7,5.4,5.3,5.6,5.7,6.5,6.4,6.2,5.8,5.8,6.5,6.3,6,5.8,5.6,5.6,5.4,6.3,6,6,5.4,5.3,5.8,5.7,5.4,5.1,5.1,5.2,5.1,5.7,5.8,5.4,4.9,4.9,5.2,5.2,4.9,4.8,4.6,4.8,4.6,5.1,5.1,4.8,4.5,4.4,4.8,5,4.6,4.4,4.1,4.3,4.3,5,4.9,4.5,4.3,4.3,4.7,4.9,4.6,4.5,4.4,4.5,4.8,5.4,5.2,5.2,4.8,5.2,5.7,6,6.1,6,6.1,6.5,7.1,8.5,8.9,9,8.6,9.1,9.7,9.7,9.6,9.5,9.5,9.4,9.7,10.6,10.4]}
Original file line number	Diff line number	Diff line change
		@@ -1 +1 @@
		Note: this uses the d3.chart module, which is deprecated. I need to rewrite the horizon component!
		An example of the [d3.horizon](https://github.com/d3/d3-plugins/tree/master/horizon) plugin.
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Note: this uses the d3.chart module, which is deprecated. I need to rewrite the horizon component!
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		{"year":[2000,2000,2000,2000,2000,2000,2000,2000,2000,2000,2000,2000,2001,2001,2001,2001,2001,2001,2001,2001,2001,2001,2001,2001,2002,2002,2002,2002,2002,2002,2002,2002,2002,2002,2002,2002,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2003,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2004,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2005,2006,2006,2006,2006,2006,2006,2006,2006,2006,2006,2006,2006,2007,2007,2007,2007,2007,2007,2007,2007,2007,2007,2007,2007,2008,2008,2008,2008,2008,2008,2008,2008,2008,2008,2008,2008,2009,2009,2009,2009,2009,2009,2009,2009,2009,2009,2009,2009,2010,2010],"month":[1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2,3,4,5,6,7,8,9,10,11,12,1,2],"rate":[4.5,4.4,4.3,3.7,3.8,4.1,4.2,4.1,3.8,3.6,3.7,3.7,4.7,4.6,4.5,4.2,4.1,4.7,4.7,4.9,4.7,5,5.3,5.4,6.3,6.1,6.1,5.7,5.5,6,5.9,5.7,5.4,5.3,5.6,5.7,6.5,6.4,6.2,5.8,5.8,6.5,6.3,6,5.8,5.6,5.6,5.4,6.3,6,6,5.4,5.3,5.8,5.7,5.4,5.1,5.1,5.2,5.1,5.7,5.8,5.4,4.9,4.9,5.2,5.2,4.9,4.8,4.6,4.8,4.6,5.1,5.1,4.8,4.5,4.4,4.8,5,4.6,4.4,4.1,4.3,4.3,5,4.9,4.5,4.3,4.3,4.7,4.9,4.6,4.5,4.4,4.5,4.8,5.4,5.2,5.2,4.8,5.2,5.7,6,6.1,6,6.1,6.5,7.1,8.5,8.9,9,8.6,9.1,9.7,9.7,9.6,9.5,9.5,9.4,9.7,10.6,10.4]}