toolkit/javascript/d3/examples/splom/splom.js
changeset 47 c0b4a8b5a012
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/examples/splom/splom.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,119 @@
+d3.json("flowers.json", function(flower) {
+
+  // Size parameters.
+  var size = 150,
+      padding = 19.5,
+      n = flower.traits.length;
+
+  // Position scales.
+  var x = {}, y = {};
+  flower.traits.forEach(function(trait) {
+    var value = function(d) { return d[trait]; },
+        domain = [d3.min(flower.values, value), d3.max(flower.values, value)],
+        range = [padding / 2, size - padding / 2];
+    x[trait] = d3.scale.linear().domain(domain).range(range);
+    y[trait] = d3.scale.linear().domain(domain).range(range.reverse());
+  });
+
+  // Axes.
+  var axis = d3.svg.axis()
+      .ticks(5)
+      .tickSize(size * n);
+
+  // Brush.
+  var brush = d3.svg.brush()
+      .on("brushstart", brushstart)
+      .on("brush", brush)
+      .on("brushend", brushend);
+
+  // Root panel.
+  var svg = d3.select("#chart").append("svg:svg")
+      .attr("width", size * n + padding)
+      .attr("height", size * n + padding);
+
+  // X-axis.
+  svg.selectAll("g.x.axis")
+      .data(flower.traits)
+    .enter().append("svg:g")
+      .attr("class", "x axis")
+      .attr("transform", function(d, i) { return "translate(" + i * size + ",0)"; })
+      .each(function(d) { d3.select(this).call(axis.scale(x[d]).orient("bottom")); });
+
+  // Y-axis.
+  svg.selectAll("g.y.axis")
+      .data(flower.traits)
+    .enter().append("svg:g")
+      .attr("class", "y axis")
+      .attr("transform", function(d, i) { return "translate(0," + i * size + ")"; })
+      .each(function(d) { d3.select(this).call(axis.scale(y[d]).orient("right")); });
+
+  // Cell and plot.
+  var cell = svg.selectAll("g.cell")
+      .data(cross(flower.traits, flower.traits))
+    .enter().append("svg:g")
+      .attr("class", "cell")
+      .attr("transform", function(d) { return "translate(" + d.i * size + "," + d.j * size + ")"; })
+      .each(plot);
+
+  // Titles for the diagonal.
+  cell.filter(function(d) { return d.i == d.j; }).append("svg:text")
+      .attr("x", padding)
+      .attr("y", padding)
+      .attr("dy", ".71em")
+      .text(function(d) { return d.x; });
+
+  function plot(p) {
+    var cell = d3.select(this);
+
+    // Plot frame.
+    cell.append("svg:rect")
+        .attr("class", "frame")
+        .attr("x", padding / 2)
+        .attr("y", padding / 2)
+        .attr("width", size - padding)
+        .attr("height", size - padding);
+
+    // Plot dots.
+    cell.selectAll("circle")
+        .data(flower.values)
+      .enter().append("svg:circle")
+        .attr("class", function(d) { return d.species; })
+        .attr("cx", function(d) { return x[p.x](d[p.x]); })
+        .attr("cy", function(d) { return y[p.y](d[p.y]); })
+        .attr("r", 3);
+
+    // Plot brush.
+    cell.call(brush.x(x[p.x]).y(y[p.y]));
+  }
+
+  // Clear the previously-active brush, if any.
+  function brushstart(p) {
+    if (brush.data !== p) {
+      cell.call(brush.clear());
+      brush.x(x[p.x]).y(y[p.y]).data = p;
+    }
+  }
+
+  // Highlight the selected circles.
+  function brush(p) {
+    var e = brush.extent();
+    svg.selectAll("circle").attr("class", function(d) {
+      return e[0][0] <= d[p.x] && d[p.x] < e[1][0]
+          && e[0][1] <= d[p.y] && d[p.y] < e[1][1]
+          ? d.species : null;
+    });
+  }
+
+  // If the brush is empty, select all circles.
+  function brushend() {
+    if (brush.empty()) svg.selectAll("circle").attr("class", function(d) {
+      return d.species;
+    });
+  }
+
+  function cross(a, b) {
+    var c = [], n = a.length, m = b.length, i, j;
+    for (i = -1; ++i < n;) for (j = -1; ++j < m;) c.push({x: a[i], i: i, y: b[j], j: j});
+    return c;
+  }
+});