Handling unix timestamp with highcharts - javascript

jsfiddle: http://jsfiddle.net/RjPRd/
Times & Labels are displayed incorrectly.
I think the timestamp should be multiplied by 1000 for Javascript Time but what's the best approach? Also I believe the setup is still incorrect because the labels seem opposite to where the cursor is.

You are right, timestamps in Javascript are milliseconds so you should multiply everything by 1000.
For the other problem it comes from the fact that your data is ordered backwards. Apparently HighCharts is messing up when the series are not properly ordered.
Here's the correction for your code: http://jsfiddle.net/cvedovini/RjPRd/2/

An easy way to work with timestamp (milliseconds) in Highcharts is use the formatter. So first receive your time values as unix timestamp and then set one of the features below in the chart:
Using in xAxis labels:
xAxis:[{
labels:{
formatter:function(){
return Highcharts.dateFormat('%Y %M %d',this.value);
}
}
}]
Using in tooltip:
tooltip: {
readerFormat: {
formatter: function(){
return Highcharts.dateFormat('%Y %M %d',this.value);
}
},
pointFormat: '{point.y} ms',
shared: true
},
An exemple of code with tooltip
A reference about formatter

Related

Tickinterval for date from json file - Highcharts

I understand we could use tick interval for type:"datetime". It works for type: category also as shown below:
http://jsfiddle.net/n0s72zeh/1/
But tick interval does not work when I use 'categories: dateFromJson'. I get custom date from json file. Is it possible to have set interval on my x-axis (like for every one hour on average ?)
xAxis: {
categories: DateFromJson,
labels: {
rotation: 270,
}
}
For eg: rite now it shows 15:06, 15:56, 15:58, instead can we make it show just 15:00?.. It should show 13:00, 14:00, 15:00 and so on(every one hour). Thank you

Plotting data on x axis in Highstock

I am currently trying to plot some data which I receive via a HTTP request. The issue that I am having is that the x-axis doesn't plot the timestamp correctly because it it's in Unix format. I've read some other similar question on SO such as: Example One
The issue is that I'm not passing an object but directly an Unix time data. When hovering the graph, you can see that the x-axis doesn't display the date and hour correctly.
Here is a fiddle with my current graph: Graph Fiddle
Since you actually have datetime values, showing them using category is sort of a hack, and would also not show gaps between points correctly if they are not evenly spaced.
Instead you could merge your two arrays into pairs and then supply it to the series as proper X-Y values for a datetime axis. You also have to multiply your datetime values by 1000 to get milliseconds, which Highcharts expects.
For example (JSFiddle), merging:
dataArray.push(selectedData);
timeDataArray.push(selectedTime);
var mergedArray = timeDataArray.map(function(e, i) {
return [e*1000, dataArray[i]];
});
And axis and series:
xAxis: {
type: 'datetime'
},
series: [{
name: 'AAPL',
data: mergedArray
}]

Incorrect values on Highcharts (compared to input)

I have a (Highcharts) graph with a percentage over time. The input for my series looks something like:
series: [{
name: "Percentage",
data: [
[1472515200000, 49],
[1472601600000, 48.83],
[1472688000000, 49.6],
[1472774400000, 48.77]
]
}]
However on the actual chart (areaspline) I get different values:
30 Aug, 48.91
31 Aug, 49.36
1 Sep, 49.6
2 Sep, 48.87
Not entirely sure why this is the case, I'm assuming it's because the graph has a datetime type and it's figuring out the average over time. Is there a way I can make the values exact as they are input? Couldn't find anything in docs
Thanks for any ideas/help/advice.
Upon further research, it seems like it's not so much a Highcharts problem but a React one. I seem to be getting different values on each render. Will look into this further and update for the curious.
Problem seemed to be related to React re-rendering and therefore recalculating my percentage values - not a Highcharts issue. Thanks for everyone who commented, bit of a wild goose chase.
Jamie, to make the input values be taken literally, you need to either leave the type value of your x-axis unset or change it to type: 'literal'.
Here's a basic fiddle I created with your data to show how it can be interpreted exactly as input (vs. converted to dates): http://jsfiddle.net/brightmatrix/vtLswcex/1/
$(function () {
Highcharts.setOptions({
lang: {
thousandsSep: ',' // adds comma for axis labels
}
});
Highcharts.chart('container', {
xAxis: {
labels: {
formatter: function() {
return Highcharts.numberFormat(this.value,0);
}
}
},
series: [{
name: "Percentage",
data: [
[1472515200000, 49],
[1472601600000, 48.83],
[1472688000000, 49.6],
[1472774400000, 48.77]
]
}]
});
});
Note that I've added formatting for the x-axis labels, as well as a thousands separator in the Highcharts.setOptions() function, so that your labels will be more easily readable as trillions.
Does this help answer your question? If you are instead looking for a better way to format time-specific data, the comment by #morganfree is well worth looking into.

Highcharts with dynamic yaxis labels as strings

I've been trying to add some custom yAxis labels to highcharts but I've not been able to so far. I've tried using formatter from a predefined array of strings and I've tried addAxis method but that doesn't get me the results I'm looking for.
Basically I have some numbers (lets say 4 and 4000) and I want to have these as my yLabels. However, I do NOT want the giant space between them. They need to be one right after the other and in ascending order. I cannot figure out how to do this leaving them as integers and I cannot figure out how to dynamically add them to highcharts as strings. I'm not even sure if this is possible
Any help would be greatly appreciated.
Here is the Y-axis label formatter documentation from Highcharts you're probably looking for. I wrote this fiddle to simulate the custom y-axis functionality you were wanting, although I'm not sure how you want to map those values to the x-axis data. This should give you a good starting point.
Code for reference:
$('#container').highcharts({
yAxis: {
categories: ['4', '4000', 'Foobar'],
labels: {
formatter: function () {
return this.value;
}
}
},
series: [{
data: [0, 1, 2]
}]
});
This stackoverflow question may also help although I noticed some dead links.

Highcharts datetime axis, how to disable time part (show only dates)?

My chart is displaying data day-by-day (user and system sent SMS/Newsletters). So time part is not relevant and unnecessary. Here is an example: http://jsfiddle.net/uaxZP/1/ where time "12:00" is displayed.
How can I force Highcharts to never display the time part in a "datetime" axis?
EDIT: Highcharts will display dates w/wo times based on chart or screen size. I've updated jsfiddle removing some data and now it's displaying also time parts.
You can intercept the x-axis label function and change it's output. In my example, I've changed it to render short dates:
http://jsfiddle.net/uaxZP/3/
{ xAxis:
labels: {
formatter: function() {
return Highcharts.dateFormat("%b %e", this.value);
}
}
}
The xAxis.labels.formatter property allows control over this. You also may notice I'm using Highcharts.dateFormat, which is a utility function for rendering dates. This is not mandatory, but it's a nice built in feature. Documentation on the xAxis formatter is here:
http://www.highcharts.com/ref/#xAxis-labels--formatter
The easiest way to do is using "minTickInterval"
xAxis: {
minTickInterval: 24 * 3600 * 1000
}
http://api.highcharts.com/highcharts#xAxis.minTickInterval

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