如何使用d3.time.scale()来生成均匀间隔日期的数组? [英] How to use d3.time.scale() to generate an array of evenly spaced dates?
问题描述
这似乎像它应该是微不足道的。我想用 d3.time.scale()
来得到均匀间隔日期覆盖一定范围内的时间的数组。例如,几年
This seems like it should be trivial. I want to use d3.time.scale()
to get an array of evenly spaced dates that covers a certain range of time. For example, years
[2012-01-01, 2013-01-01, 2014-01-01]
或几个月
[2012-01-01, 2012-02-01, 2012-03-01 ... 2014-12-01]
或什么的。
于是,我开始像这样:
var t = d3.time.scale()
.domain(d3.extent(dates))
.nice(d3.time.year);
然后我会从文档假设的我' d是能够做到这一点。
I would then assume from the documentation that I'd be able to do this
var ticks = t.ticks(d3.time.month,1);
...但只返回一个日期。
...but that just returns a single date.
这给了我几个月的数组
var ticks = t.ticks(30)
...但只是因为我告诉它大概有多少蜱生成(30),我不会事先知道(除非我做一些繁重的我自己,哪一种违背了使用D3的目的为了这)。
...but only because I told it roughly how many ticks to generate (30), which I won't know in advance (unless I do some heavy lifting on my own, which kind of defeats the purpose of using d3 for this).
我不明白为什么它不工作,每年只需告诉它我想,或每月或每3个月,或什么的。
I don't understand why it's not working to just tell it that I want every year, or every month, or every 3 months, or whatever.
我在这里提出了一个小提琴: http://jsfiddle.net/herbcaudill/LgGpd/ 4 /
I've put up a fiddle here: http://jsfiddle.net/herbcaudill/LgGpd/4/
推荐答案
使用Date()构造不正常 - 它基本上依赖于浏览器。这是更安全的明确解析。构造函数不分析这样。
Using the Date() constructor doesn't work reliably -- it basically depends on the browser. It's much safer to parse explicitly. The constructor doesn't parse as such.
而不是
var dates = getDates().map(function(d) { return new Date(d) });
使用:
var dates = getDates().map(function(d) {
return d3.time.format("%Y-%m-%d").parse(d);
});
修改的jsfiddle 这里。
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