--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/javascript/d3/src/scale/log.js	Thu Apr 10 14:20:23 2014 +0200
@@ -0,0 +1,85 @@
+d3.scale.log = function() {
+  return d3_scale_log(d3.scale.linear(), d3_scale_logp);
+};
+
+function d3_scale_log(linear, log) {
+  var pow = log.pow;
+
+  function scale(x) {
+    return linear(log(x));
+  }
+
+  scale.invert = function(x) {
+    return pow(linear.invert(x));
+  };
+
+  scale.domain = function(x) {
+    if (!arguments.length) return linear.domain().map(pow);
+    log = x[0] < 0 ? d3_scale_logn : d3_scale_logp;
+    pow = log.pow;
+    linear.domain(x.map(log));
+    return scale;
+  };
+
+  scale.nice = function() {
+    linear.domain(d3_scale_nice(linear.domain(), d3_scale_niceDefault));
+    return scale;
+  };
+
+  scale.ticks = function() {
+    var extent = d3_scaleExtent(linear.domain()),
+        ticks = [];
+    if (extent.every(isFinite)) {
+      var i = Math.floor(extent[0]),
+          j = Math.ceil(extent[1]),
+          u = Math.round(pow(extent[0])),
+          v = Math.round(pow(extent[1]));
+      if (log === d3_scale_logn) {
+        ticks.push(pow(i));
+        for (; i++ < j;) for (var k = 9; k > 0; k--) ticks.push(pow(i) * k);
+      } else {
+        for (; i < j; i++) for (var k = 1; k < 10; k++) ticks.push(pow(i) * k);
+        ticks.push(pow(i));
+      }
+      for (i = 0; ticks[i] < u; i++) {} // strip small values
+      for (j = ticks.length; ticks[j - 1] > v; j--) {} // strip big values
+      ticks = ticks.slice(i, j);
+    }
+    return ticks;
+  };
+
+  scale.tickFormat = function(n, format) {
+    if (arguments.length < 2) format = d3_scale_logFormat;
+    if (arguments.length < 1) return format;
+    var k = n / scale.ticks().length,
+        f = log === d3_scale_logn ? (e = -1e-15, Math.floor) : (e = 1e-15, Math.ceil),
+        e;
+    return function(d) {
+      return d / pow(f(log(d) + e)) < k ? format(d) : "";
+    };
+  };
+
+  scale.copy = function() {
+    return d3_scale_log(linear.copy(), log);
+  };
+
+  return d3_scale_linearRebind(scale, linear);
+};
+
+var d3_scale_logFormat = d3.format("e");
+
+function d3_scale_logp(x) {
+  return Math.log(x) / Math.LN10;
+}
+
+function d3_scale_logn(x) {
+  return -Math.log(-x) / Math.LN10;
+}
+
+d3_scale_logp.pow = function(x) {
+  return Math.pow(10, x);
+};
+
+d3_scale_logn.pow = function(x) {
+  return -Math.pow(10, -x);
+};