Add bubble chart extension

extensions/chart-bubble/bubble.js

+(function() {
+    var extra = {};
+
+    c3.chart.internal.fn.additionalConfig = {
+        data_pairs: [],
+    };
+
+    c3.chart.internal.fn.beforeInit = function (config) {
+
+        var that = this;
+
+        // update internals only when chart type is "bubble"
+        if (config.data.type !== 'bubble') {
+            return;
+        }
+
+        // Set extra to ba able to be used in other part
+        this.extra = extra;
+
+        extra.getKey = function (x, y) {
+            return x + '::' + y;
+        };
+
+        this.config.data_type = 'scatter';
+
+        this.config.axis_x_padding = 0;
+        this.config.axis_y_padding = 0;
+        this.config.axis_x_tick_centered = true;
+        this.config.axis_x_tick_format = function (d) {
+            return extra.names[d];
+        };
+        this.config.axis_y_tick_format = function (d) {
+            return extra.names[d];
+        };
+
+        if (!config.color || !config.color.pattern) {
+            this.config.color_pattern = ['#1f77b4'];
+        }
+
+        this.config.point_r = function (d) {
+            var names = extra.names, values = extra.values, base_length = extra.base_length,
+                x = names[d.x], y = d.id, key = extra.getKey(x, y), max, min, a, value, r;
+
+            if (!base_length) {
+                base_length = extra.base_length = d3.min([
+                    that.svg.select('.c3-axis.c3-axis-y path').node().getTotalLength(),
+                    that.svg.select('.c3-axis.c3-axis-x path').node().getTotalLength(),
+                ]);
+            }
+
+            max = d3.max(Object.keys(values).map(function (key) { return values[key]; }));
+            min = d3.min(Object.keys(values).map(function (key) { return values[key]; })),
+            a = ((base_length / (names.length * 2)) - 1) / (Math.log(max + 1) - Math.log(min + 1));
+
+            value = !values[key] ? 0 : values[key];
+            r = (Math.log(value + 1) - Math.log(min + 1)) * a;
+
+            return r > 0 ? r : 0;
+        };
+        this.config.point_sensitivity = 25;
+        this.config.point_focus_expand_enabled = false;
+
+        this.config.legend_show = false;
+
+        if (!config.tooltip || !config.tooltip.contents) {
+            this.config.tooltip_contents = function (d, defaultTitleFormat, defaultValueFormat, color) {
+                var x = extra.names[d[0].x], y = d[0].name, v = extra.values[extra.getKey(x, y)], text;
+
+                text = "<table class='" + this.CLASS.tooltip + "'>";
+                text += "<tr><th colspan='2'>" + x + "&nbsp;/&nbsp;" + y + "</th></tr>";
+                text += "<tr><td class='value'>" + (!v ? 0 : v) + "</td></tr>";
+                text += "</table>";
+
+                return text;
+            };
+        }
+
+        // construct bubble chart data and setup config based on the values
+
+        var xs = this.config.data_pairs.map(function (pair) { return pair.x; }),
+            ys = this.config.data_pairs.map(function (pair) { return pair.y; });
+
+        extra.names = d3.set(xs.concat(ys)).values().sort();
+
+        this.config.axis_y_tick_values = extra.names.map(function (name, i) { return i; });
+
+        var data_xs = {};
+        extra.names.forEach(function (name) {
+            data_xs[name] = name + '_x';
+        });
+        var data_columns_xs = Object.keys(data_xs).map(function (key) {
+            return [data_xs[key]].concat(extra.names.map(function (name, i) { return i; }));
+        });
+        var data_columns_values = extra.names.map(function (name, i) {
+            return [name].concat(extra.names.map(function (name) { return i; }));
+        });
+        this.config.data_xs = data_xs;
+        this.config.data_columns = data_columns_xs.concat(data_columns_values);
+
+        var values = {};
+        this.config.data_pairs.forEach(function (pair) {
+            if (!pair.x || !pair.y) {
+                throw "x and y are required in data.";
+            }
+            values[extra.getKey(pair.x, pair.y)] = pair.value;
+        });
+        extra.values = values;
+
+        this.config.axis_x_min = this.config.axis_y_min = -0.5;
+        this.config.axis_x_max = this.config.axis_y_max = extra.names.length - 0.5;
+    };
+})(window);

extensions/chart-bubble/c3.css

+../../c3.css
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extensions/chart-bubble/c3.min.js

+../../c3.min.js
\ No newline at end of file

extensions/chart-bubble/index.html

+<html>
+  <head>
+    <link rel="stylesheet" type="text/css" href="c3.css">
+  </head>
+  <body>
+    <div id="chart"></div>
+
+    <script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>
+    <script src="c3.min.js"></script>
+    <script src="bubble.js"></script>
+    <script>
+     var chart = c3.generate({
+         data: {
+             type: 'bubble',
+             pairs: [
+                 { x: 'Name_0', y: 'Name_0', value: 10000 },
+                 { x: 'Name_0', y: 'Name_1', value: 20000 },
+                 { x: 'Name_0', y: 'Name_2', value: 39990 },
+//                 { x: 'Name_1', y: 'Name_0', value: 5000 },
+                 { x: 'Name_1', y: 'Name_1', value: 6000 },
+                 { x: 'Name_1', y: 'Name_2', value: 50000 },
+                 { x: 'Name_2', y: 'Name_0', value: 1000 },
+                 { x: 'Name_2', y: 'Name_1', value: 20000 },
+                 { x: 'Name_2', y: 'Name_2', value: 30000 },
+             ]
+         },
+         grid: {
+             x: {
+                 show: true
+             },
+             y: {
+                 show: true
+             }
+         },
+      });
+    </script>
+  </body>
+</html>