Highcharts X-Axis Issue - javascript

I have googled and searched stack overflow alot before deciding to ask this question here because while some questions seemed similar, none of the solutions worked for me.
I have categorised data from sometimes a very wide range eg 1881 - 2012 and would like to dynamically calculate and divide this range into only 11 points on the x-axis which is what I have room to display with no zooming enabled. If data is from from 1881 - 2012, I would like it for example want it to show(not exactly calculated) from 1881, 1901, 1921, 1941.....if its from 1958 - 2013, then 1958, 1968, 1978....
xAxis: {
categories: range(start_year,end_year),
tickmarkPlacement: "on",
tickInterval: Math.ceil(range(start_year,end_year).length/11),
},
.......
function range(start_year,end_year)
{
var years = [];
for(var i = start_year;i<=end_year;i++)
{
years.push(i);
}
return years;
}
What this code does is just skip the labels for certain years but still plots the points on the graph leading to overlapping years on the x-axis.
Any leads on this would be highly appreciated.
Here's the fiddle illustrating my dilemma http://jsfiddle.net/YUPzk/4/

You can use tickPositioner and prepare your own calculating function.
The JavaScript below is one example of how this can be done:
Highcharts.chart('container', {
title: {
text: 'Custom tick positions'
},
subtitle: {
text: 'through axis.tickPositions and axis.tickPositioner'
},
xAxis: {
tickPositions: [0, 1, 2, 4, 8]
},
yAxis: {
tickPositioner: function () {
var positions = [],
tick = Math.floor(this.dataMin),
increment = Math.ceil((this.dataMax - this.dataMin) / 6);
if (this.dataMax !== null && this.dataMin !== null) {
for (tick; tick - increment <= this.dataMax; tick += increment) {
positions.push(tick);
}
}
return positions;
}
},
series: [{
data: [ [0, 1],[1, 3],[2, 2],[4, 4],[8, 3] ]
}]
});
The above demo code can be found at this jsfiddle

For anyone else struggling to get this done, here's what you need because i did lot's of googling with no answers to be found for people experiencing same challenge
Highcharts ; x-axis scaling issue

Related

How to make yAxis column start with value min yAxis in Highcharts?

I use Highcharts to plot the graph, but there is a problem I am facing. data contains the values from 1 to n. So I want the yAxis column to start at 1. I set yAxis min = 1 but it doesn't fix my problem.
Here is a jsfiddle that illustrates the problem I am having:
Link
yAxis: {
title: null,
endOnTick: false,
min: 1
}
Is there any way to solve my problem? I expect it like this:
I expect it like this
The simplest solution is to use tickPositioner function and modify the first tick. For example:
yAxis: {
title: null,
tickPositioner: function() {
const tickPositions = [...this.tickPositions];
tickPositions[0] = 1;
return tickPositions;
},
endOnTick: false,
startOnTick: false,
min: 1
}
Live demo: https://jsfiddle.net/BlackLabel/rf3cm8Lw/
API Reference: https://api.highcharts.com/highcharts/xAxis.tickPositioner
Thanks for ppotaczek answer. I find it pretty cool, can ignore blanks, starting from the smallest element. I have a solution for this and am posting it here for anyone who needs it.
tickPositioner: function () {
var positions = [],
tick = Math.floor(this.dataMin),
increment = Math.ceil((this.dataMax - this.dataMin) / 6);
if (this.dataMax !== null && this.dataMin !== null) {
for (tick; tick - increment <= this.dataMax; tick += increment) {
positions.push(tick);
}
}
return positions;
}

Highcharts yAxis.max manage tick intervals dynamically

I'm trying to set the max and min of y value dynamically based on the data but it is having some troubles for some values. I think the highchart couldn't set values that doesn't have a proper tick.
For eg: min: 3 and max 10. Then, the highchart won't set these values instead of that it will set a value ranging from 0...14. This is just an example value, sometimes I get 36000.14 as min and 454533.18 as max.
So my logic isn't working in that case.
This is the part of code which I currently have:
data = [3.43, 3.58, 4.86, 8.55, 8.77, 4.44, 9.67]
maximum_val = Math.ceil(maximum_val) eg: 10
minimum_val = Math.floor(minimum_val) eg: 3
evolution_options.yAxis[$('#div_count_'+div).find('#y_axis_lbl').text()] = {
min: minimum_val,
max: maximum_val,
title: false,
labels: {
style: {
color: 'black'
}
}
}
Update
Fiddle : http://jsfiddle.net/e3fy1vu9/
Further Brainstorming
I think it is because the min value isn't a multiple of the max value so Highchart couldn't calculate how to split the tick. If there was any way so I could set the max value as the multiple of the min value.
Here is my advice how to calculate the max and min for yAxis from the defined data.
Demo: https://jsfiddle.net/BlackLabel/0qwt1kx7/
yAxis: {
min: Math.floor(Math.min(...data)),
max: Math.round(Math.max(...data)),
tickAmount: Math.round(Math.max(...data)) - Math.floor(Math.min(...data)) + 1 //1 count the min or max as itself
},
Please test it and let me know if it fits to your requirements. Because the tickAmount value depends on how many values is included in the data array and probably some modifications are needed for larger data.
EDIT:
Try to use this custom solution to calculate the yAxis positions:
Demo: http://jsfiddle.net/BlackLabel/ztaj6Lkd/
var positions = [],
tickNumbers = 5,
tick = Math.floor(Math.min(...data));
for(let i = 0; i < tickNumbers; i++) {
positions.push((Math.round(tick * 100) / 100));
tick += Math.round(Math.max(...data)) / tickNumbers
}
//add the max
positions.push(Math.round(Math.max(...data)))
Hi I have fixed it by setting this alignTicks:false option.
evolution_options.yAxis[$('#div_count_'+div).find('#y_axis_lbl').text()] = {
min: minimum_val,
max: maximum_val,
title: false,
labels: {
style: {
color: 'black'
}
},
alignTicks: false
}

Long array of small data points is rendered as a jagged line

The Goal
I'm attempting to render a long series of data (around 200 ticks, from small float values like 1.3223) into a line chart.
The Issue
When I use a series of data that changes only a small amount (around 0.0001 every tick), the chart is rendered as very jagged (scissor like). I would like to somehow fix it to have a "saner" radius between each point on the graph.
A Good Example
On the other hand, when rendering higher values (around 1382.21) with bigger difference between ticks (from 0.01 to 0.05 +/-) the graph is rendered more smooth and aesthetically pleasing.
Edit: As user Arie Shaw pointed out, the actual low or high values don't make a difference and it remains an issue of representing small "monotonous" changes is a less jagged form.
The Code
var initChart = function(data, container) {
new Highcharts.Chart({
chart: {
type: "area",
renderTo: container,
zoomType: 'x'
},
title: {
text: ''
},
xAxis: {
labels: {
enabled: false
}
},
yAxis: {
title: {
text: ''
}
},
legend: {
enabled: false
},
color: '#A3D8FF',
plotOptions: {
area: {
fillColor: '#C6E5F4',
lineWidth: 1,
marker: {
enabled: false
},
shadow: false,
states: {
hover: {
lineWidth: 1
}
},
threshold: null
}
},
exporting: {
enabled: false
},
series: [{
name: "TEST",
data: data
}]
});
};
Both graphs, and sample data sets are presented in the following fiddle:
http://jsfiddle.net/YKbxy/2/
The problem you're experiencing is unavoidable: If you have a lot of small variations over time, the graph is going to appear jagged provided that you show each data point.
The key point is that last phrase.
One way to 'smooth out' the rough parts would be to average the data. For example:
var myData = []; //... Some array of data; assuming just numbers
var averageData = function (data, factor) {
var i, j, results = [], sum = 0, length = data.length, avgWindow;
if (!factor || factor <= 0) {
factor = 1;
}
// Create a sliding window of averages
for(i = 0; i < length; i+= factor) {
// Slice from i to factor
avgWindow = data.slice(i, i+factor);
for (j = 0; j < avgWindow.length; j++) {
sum += avgWindow[j];
}
results.push(sum / avgWindow.length)
sum = 0;
}
return results;
};
var var initChart = function(data, container) {
new Highcharts.Chart({
series: [{
name: "TEST",
data: averageData(myData, 2)
}]
});
});
This method also has the advantage that you could (potentially) reuse the function to compare the averaged data to the regular data, or even toggle between how much to average the data.
You can always use areaspline instead of area, see: http://jsfiddle.net/YKbxy/3/
why dont you treat you .00001 data as 1, so times 10000, and then write it in your legend like that.
You should even do that as a test, since if the chart looks fine then, it means there is a problem in the dataset numbers when you return it to normal, since high charts takes the difference between high and low...
Either you must approximate your data by only using a few decimal places or you must average out the values using something like:
var data = new Array(200);
var smallArray = new Array(5);
var averagedData = new Array(20);
for (var index=0; index<=averagedData.length; index++){
for(var i = 0; i<=smallArray.length; i++){
smallArray[i] = data[i + index * 5];
}
averagedData[index] = (smallArray[1] + smallArray[2] + smallArray[3] + smallArray[4] + smallArray[5])/smallArray.length;
}
Then you will only need to plot 20 averaged points on an array of 200 data points. You can change the values for what you need.
In the end the issue is in the frequency of the points or their plotting on yAxis.
When I provide more realistic positioning (e.g timestamp) it will look good.
Meaning that jaggedness is a result of the small changes over constant yAxis progression, which is most similar to nt3rp's answer

Flowing Merge of points with same x-axis in the same series

I am currently using highstock to plot the total number of items available based on time throughout the day (which then updates real-time).
If two changes to the total number of items happens at the same time, in highstock I get a vertical bar of the difference:
So in my example image we start with 4299 things, then 53 items are removed and 50 are added (technically at the same time, but are two different transactions and are two points). With a net difference of -3. (or in otherwords, I get {x: 5:44:15 and y: 4246, change: -53}, {x: 5:44:15, y: 4296, change: 50}).
So my question:
Is it possible in highstock to merge those points to get rid of the vertical bar and use 4296 as the shown value? I was hoping I could then use the tooltip formatter to loop through 'this.points' and display a change of -53 and a change of 50 in the tooltip so the user can see what resulted in a net change of -3.
If this is not possible, I will just merge the points myself and pass all the relevant information in the point to generate the tooltip (and chart look) that I am going for, but wanted to see if I could just utilize all the functionality of highstock first - and keep these points separate.
Thanks!
Edit::
new Highcharts.StockChart({
chart : {
renderTo : 'realTimeChart',
zoomType: 'x',
backgroundColor: '#feffdd',
style: {
fontFamily: 'Segoe UI'
},
type: 'spline'
},
plotOptions: {
area: { animation: false },
arearange: { animation: false },
areaspline: { animation: false },
areasplinerange: { animation: false },
bar: { animation: false },
column: { animation: false },
columnrange: { animation: false },
gauge: { animation: false },
line: { animation: false },
pie: { animation: false },
scatter: { animation: false },
series: { animation: false },
spline: { animation: false }
},
xAxis: {
ordinal: false
},
tooltip: {
animation: false,
formatter: function() {
var p = '';
p += '<span style="font-size: 9px;">' + Highcharts.dateFormat('%A, %b %e, %Y %H:%M:%S', this.x) +'</span><br/>';
$.each(this.points, function(i, point){
p += '<span style="color:' + this.series.color + '">' + this.series.name + '</span>: <b>'+ this.y +'</b>';
if (point.point.where) {
p += '<br />' + point.point.where + ' changed by ' + point.point.change + (point.point.who ? ' (' + point.point.who + ')' : '');
}
});
return p;
}
},
rangeSelector: {
buttons: [{
count: 30,
type: 'minute',
text: '30M'
}, {
count: 1,
type: 'hour',
text: '1H'
}, {
count: 6,
type: 'hour',
text: '6H'
}, {
type: 'all',
text: 'Day'
}],
inputEnabled: false,
selected: 1
},
exporting: {
enabled: false
},
series : [{
name : 'Available',
data : data,
lineWidth: 1,
states: {
hover: {
enabled: false
}
}
}]
Data is in the format I showed previously, except the x is actually in milliseconds since epoch:
data = [
{x: 123456789, y: 2000, where: 'Location', change: 40, who: 'Joe'},
{x: 123456789, y: 1960, where: 'Location', change: -40, who: 'Bob'},
...
];
Just wanted to follow up with how I easily got around the probem. Instead of placing by second, I decided to group points together to the nearest minute rounding down (so I have blocks of minutes).
Then for each point I passed in an array of the actual points contained within that minute block as a new argument, and updated the y value for that minute block. Then I used the tooltip formatter to display all the changes within that minute block with their actual time of change. This gave me a more flowing graph instead of all these hard vertical points for the same x-axis.
To easily change a data point at a specific x-axis point, I kept a separate array of the location of the minute block inside the series.data array for highcharts, that way if I needed to update a block, I knew exactly where that time series was.
Here is how I accomplished my task:
I create the reference array:
var pointIndex = {};
I created the inital data series from historical data for the day (pulled in via ajax):
var data = [];
var time = Math.floor(actual_time / 60000) * 60000;
pointIndex[time] = data.push({x: time, y: items_available, change: [{when: actual_time}]});
So actual_time is the number of milliseconds since epoch (when the even change occured), then I round that to the nearest minute to get the minute time block, change is the argument that will hold all the actual points for display in the tooltip.
So when I add a new point I check if the minute block exists, if it does not, add a new point, otherwise update an old point:
var time = (new Date()).getTime();
var point = Math.floor(time / 60000) * 60000;
if (pointIndex[point]) {
var change = chart.series[0].data[pointIndex[point]].change;
change.push({when: time});
chart.series[0].data[pointIndex[point]].update({x: point, y: items_available, change: change});
} else {
pointIndex[point] = chart.series[0].data.length;
chart.series[0].addPoint({x: point, y: items_available, change: [{when: time}]}, false, false);
}
(In all cases I do the actual chart refresh after I am done updating points.)
Hopefully that will help anyone else who finds theirself in the same position!
Edit:: (forgot the formatter):
tooltip: {
animation: false,
formatter: function() {
var p = '';
p += '<span style="font-size: 9px;">' + Highcharts.dateFormat('%A, %b %e, %Y %H:%M', this.x) +'</span><br/>';
$.each(this.points, function(i, point){
p += '<span style="color:' + this.series.color + '">' + this.series.name + '</span>: <b>'+ this.y +'</b>';
if (point.point.change) {
for(var j = 0; j < point.point.change.length; ++j) {
p += '<br />Change at: ' + new Date(point.point.change[j].when).toTimeString();
}
}
});
return p;
}
}

jqPlot points not correct when numberTicks set

I'm trying to limit the number of ticks on a dynamic jqplot I'm setting up. Unfortunately, when I do it, the points do not look accurate. Here's what it looks like:
As you can see, the point on 10/05/12, for example, is not on it's correct axis. I realize that now these points are estimated, but the points must look accurate on the graph -- especially when hovering over the points gives you their correct date and y-axis value.
Here's my code for this intilization, if that helps:
var datepickerBegin = $("#datepicker_start").datepicker({dateFormat: "dd/mm/yyyy"}).val();
var datepickerEnd = $("#datepicker_to").datepicker({dateFormat: "dd/mm/yyyy"}).val();
var startDiff = $("#datepicker_start").datepicker("getDate");
var endDiff = $("#datepicker_to").datepicker("getDate");
alert(startDiff)
alert(endDiff)
// Check if dates are more than a week apart
if(endDiff - startDiff >= 15 * 86400 * 1000) {
var plot2 = $.jqplot('chart2', jsonurl,{
title: "Storage Space",
dataRenderer: ajaxDataRenderer,
dataRendererOptions: {unusedOptionalUrl: jsonurl},
axes: {
xaxis: {
'numberTicks' : 15,
min: datepickerBegin,
max: datepickerEnd,
renderer:$.jqplot.DateAxisRenderer,
rendererOptions:{tickRenderer:$.jqplot.CanvasAxisTickRenderer},
tickInterval: '1 day',
tickOptions:{formatString:'%#m/%#d/%Y'
}
},
yaxis: {
label: "MB",
tickOptions:{formatString:'%d '},
min: 0
}
},
highlighter: {
show: true,
sizeAdjust: 7.5
}
});
// Somehow fix the line?
plot2.redraw({});
}
Anyone out there have a fix for this? Thanks!

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