在 D3.js 中,我目前正在尝试根据数据数组是否包含该时间来填充一个空数组(数组仅包含每 5 分钟后的时间戳)。如果数据数组包含时间,则应复制该值,否则为 null。但是当我尝试比较两个时间对象时,它无法正常工作。
以下是代码(当前代码不是复制值而是打印以便于调试):
var data = [{"mytime": "2015-12-01T23:10:00.000Z", "value": 64},
{"mytime": "2015-12-01T23:15:00.000Z", "value": 67},
{"mytime": "2015-12-01T23:20:00.000Z", "value": 70},
{"mytime": "2015-12-01T23:25:00.000Z", "value": 64},
{"mytime": "2015-12-01T23:30:00.000Z", "value": 72},
{"mytime": "2015-12-01T23:35:00.000Z", "value": 75},
{"mytime": "2015-12-01T23:40:00.000Z", "value": 71},
{"mytime": "2015-12-01T23:45:00.000Z", "value": 80},
{"mytime": "2015-12-02T00:00:00.000Z", "value": 80},
{"mytime": "2015-12-02T00:05:00.000Z", "value": 85}
];
var parseDate = d3.time.format("%Y-%m-%dT%H:%M:%S.%LZ").parse;
data.forEach(function(d) {
d.mytime = parseDate(d.mytime);
});
var act_data = [];
var x_extent = d3.extent(data, function(d){
return d['mytime']});
time_arr = d3.time.minute.range(x_extent[0],x_extent[1],5);
for(var key in time_arr){
var temp;
temp = contains(data,time_arr[key],'mytime');
}
function contains(data,value,variable)
{
var i =data.length;
while(i--){
if (data[i][variable] === value)
{
console.log('found');
return i;
}
}
return false;
}
输出应该是这样的:
data = [{"mytime": "2015-12-01T23:10:00.000Z", "value": 64},
{"mytime": "2015-12-01T23:15:00.000Z", "value": 67},
{"mytime": "2015-12-01T23:20:00.000Z", "value": 70},
{"mytime": "2015-12-01T23:25:00.000Z", "value": 64},
{"mytime": "2015-12-01T23:30:00.000Z", "value": 72},
{"mytime": "2015-12-01T23:35:00.000Z", "value": 75},
{"mytime": "2015-12-01T23:40:00.000Z", "value": 71},
{"mytime": "2015-12-01T23:45:00.000Z", "value": 80},
{"mytime": "2015-12-01T23:50:00.000Z", "value": null},
{"mytime": "2015-12-01T23:55:00.000Z", "value": null},
{"mytime": "2015-12-02T00:00:00.000Z", "value": 80},
{"mytime": "2015-12-02T00:05:00.000Z", "value": 85}
];
最佳答案
您可以使用(D3 3.x API)
-
d3.time.format
解析和格式化您的日期 -
d3.extent
确定时间戳的边界 -
d3.time.scale
生成您想要输出的报价 - 和
d3.map
对您的输入进行哈希处理并确定值是否存在
这给了我们
var data = [...];
// for parsing and formatting
var timeformat = d3.time.format("%Y-%m-%dT%H:%M:%S.%LZ");
// range to operate on
var extent = d3.extent(data, function(d){
return timeformat.parse(d.mytime);
});
// scale representing the time stamps
var scale = d3.time.scale()
.domain(extent) // the boundaries
.ticks(d3.time.minute, 5); // 5 minutes intervals
// easier to determine if a value exists
var hashed = d3.map(data, function(d) { return d.mytime; });
// or if your version < 3.5
/*
var hashed = d3.map();
data.forEach(function(d) {
hashed.set(d.mytime, d);
});
*/
// transforms the scale into the desired output
var res = scale.map(function(t) {
var ft = timeformat(t);
return {
mytime: ft,
value: (hashed.has(ft)) ? hashed.get(ft).value : null
};
});
还有一个演示 http://jsfiddle.net/nikoshr/qxcLry8z/
var data = [
{"mytime": "2015-12-01T23:10:00.000Z", "value": 64},
{"mytime": "2015-12-01T23:15:00.000Z", "value": 67},
{"mytime": "2015-12-01T23:20:00.000Z", "value": 70},
{"mytime": "2015-12-01T23:25:00.000Z", "value": 64},
{"mytime": "2015-12-01T23:30:00.000Z", "value": 72},
{"mytime": "2015-12-01T23:35:00.000Z", "value": 75},
{"mytime": "2015-12-01T23:40:00.000Z", "value": 71},
{"mytime": "2015-12-01T23:45:00.000Z", "value": 80},
{"mytime": "2015-12-02T00:00:00.000Z", "value": 80},
{"mytime": "2015-12-02T00:05:00.000Z", "value": 85}
];
var timeformat = d3.time.format("%Y-%m-%dT%H:%M:%S.%LZ");
var extent = d3.extent(data, function(d){
return timeformat.parse(d.mytime);
});
var scale = d3.time.scale()
.domain(extent)
.ticks(d3.time.minute, 5);
var hashed = d3.map();
data.forEach(function(d) {
hashed.set(d.mytime, d);
});
var res = scale.map(function(t) {
var ft = timeformat(t);
return {
mytime: ft,
value: (hashed.has(ft)) ? hashed.get(ft).value : null
};
});
var $table = $('<table></table>');
res.forEach(function(d) {
$table.append('<tr><td>'+d.mytime+'</td><td>'+d.value+'</td></tr>')
});
$('body').append($table);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>
关于javascript - 比较 D3.js 中的两个时间对象,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/36307553/