Merge branch 'fix-log-precision' into release

d3.js

@@ -2542,7 +2542,7 @@ function d3_scale_log(linear, log) {
     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),
+        f = log === d3_scale_logn ? (e = -1e-12, Math.floor) : (e = 1e-12, Math.ceil),
         e;
     return function(d) {
       return d / pow(f(log(d) + e)) < k ? format(d) : "";

src/scale/log.js

@@ -52,7 +52,7 @@ function d3_scale_log(linear, log) {
     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),
+        f = log === d3_scale_logn ? (e = -1e-12, Math.floor) : (e = 1e-12, Math.ceil),
         e;
     return function(d) {
       return d / pow(f(log(d) + e)) < k ? format(d) : "";

test/scale/log-test.js

@@ -162,6 +162,10 @@ suite.addBatch({
           "7e-3", "8e-3", "9e-3", "1e-2", "2e-2", "3e-2", "4e-2", "5e-2",
           "6e-2", "7e-2", "8e-2", "9e-2", "1e-1", "2e-1", "3e-1", "4e-1"
         ]);
+        var x = log().domain([.95, 1.05e8]);
+        assert.deepEqual(x.ticks().map(x.tickFormat(8)).filter(String), [
+          '1e+0', '1e+1', '1e+2', '1e+3', '1e+4', '1e+5', '1e+6', '1e+7', '1e+8'
+        ]);
       },
       "can generate fewer ticks, if desired": function(log) {
         var x = log();