Develop Reference

How to highlight specific Point with Highcharts Js

I have a simple Highchart with a dataset of up to 1000 datas. There are only y values the x values are generated automatically. Also, the values come from my nodejs server so please don't be surprised about the notation.
Now I want 3 special values whose x and y values are known to be highlighted. In which way doesn't matter for now.
One possibility would be to show the point at the location, otherwise they are not displayed. The problem I have is that I don't know how to control a specific point.
var chart1 = new Highcharts.Chart({
chart: {
renderTo: 'chart-emg1',
type: 'line'
},
title: {
text: 'EMG 1'
},
xAxis: {
tickInterval: 1
},
yAxis: {
title: { text: 'Voltage'}
},
series: [{
data: [<%-data1 %>]
}]
});

You can use the load event and update specific points. For example:
events: {
load: function() {
this.series[0].points.forEach(point => {
const isPointToHighlight = pointsToHighlight.some(
p => p.x === point.x && p.y === point.y
);
if (isPointToHighlight) {
point.update({
color: 'red',
marker: {
enabled: true
}
}, false);
}
});
this.redraw();
}
}
Live demo: http://jsfiddle.net/BlackLabel/tLd3j78f/
API Reference:
https://api.highcharts.com/highcharts/chart.events.load
https://api.highcharts.com/class-reference/Highcharts.Point#update

Chart update everytime on Loading second array : Highcharts, Javascript

So, What I have is a condition in a MySQL to show the first 1000 data points first and then the other 2000 datapoints after that in Highcharts.
if lastindex==0:
cur.execute("SELECT data,value FROM table where id<1001")
else:
cur.execute("SELECT data,value FROM table where id>1001 and id<3000")
data = cur.fetchall()
//python Code to fetch SQL data
Now what I am doing is that I am rendering that data into the Highcharts, the data is being rendered. but the problem arises that after showing the first 1000 data points, the Highcharts value starts from 0 and then shows the other 2000 points
the data is not displaying continuously as it should plot the send array data just after the end of the first data.
I think the Highcharts is being called Twice, What can I do to append the 2nd set of data to the first set without reloading the whole chart.
Here's a snip of my Highchart's js
Highcharts.chart("chartcontainer", {
chart: {
type: 'line',
animation: Highcharts.svg, // don't animate in old IE
marginRight: 10,
events: {
load: function() {
var series = this.series[0],
chart = this;
setInterval(function() {
//some logic regarding the chart
//..
v = {
y: y,
x: x
};
console.log("V value", v);
series.addSeries(v, false, true);
counter++;
localcounter++;
} else
{
oldcounter=counter;
flagToreload=1;
}
}, 1000/130);
setInterval(function() {
chart.redraw(false);
}, 100);
}
}
},
time: {
useUTC: false
},
title: {
text: 'Live random data'
},
xAxis: {
type: 'Value',
gridLineWidth: 1
},
yAxis: {
title: {
text: 'Value'
},
plotLines: [{
value: 0,
width: 1,
color: '#808080'
}],
gridLineWidth: 1
},
tooltip: {
headerFormat: '<b>{series.name}</b><br/>',
pointFormat: '{point.x:%Y-%m-%d %H:%M:%S}<br/>{point.y:.2f}'
},
exporting: {
enabled: false
},
series: [{
animation: false,
name: 'Random data',
data: (function() {
// generate an array of random data
var data = [],
time = counter,
i;
for (i = -1000; i <= 0; i += 1) {
data.push([
counter,
null
]);
}
return data;
}())
}]
});
What I want is just to append the event data rather than loading the whole chart.
How can I reload a particular Highchart value without reloading the whole chart ?

What do you think about updating the current series with new data, which will be an array of old data merged with the new one?
chart: {
events: {
load(){
let chart = this,
currentSeries = chart.series[0],
newData;
newData = [...currentSeries.userOptions.data, ...data1]
setTimeout(()=> {
chart.series[0].update({
data: newData
})
}, 5000)
}
}
},
See the demo

HighCharts with Dynamic Data not working

I have a ASP.NET MVC project with SignalR.
I have a page with a HighChart and the script looks like this:
$(function () {
window.Highcharts.setOptions({
global: {
useUTC: false
}
});
var chart;
$(document).ready(function () {
chart = new Highcharts.Chart({
chart: {
renderTo: 'container',
type: 'line',
marginRight: 10
},
title: {
text: 'GMAS Queues'
},
xAxis: {
type: 'datetime',
tickInterval: 500,
labels: {
enabled: false
}
},
yAxis: {
title: {
text: 'Queue Count'
},
plotLines: [{
value: 0,
width: 1,
color: '#808080'
}]
},
legend: {
enabled: false
},
exporting: {
enabled: false
},
series: [{
name: 'Processing Queues'
}]
});
});
$.connection.hub.logging = true;
// Reference the auto-generated proxy for the hub.
var chartData = $.connection.processingQueuesHub;
// Create a function that the hub can call back to display messages.
chartData.client.updateQueueCounts = function (data) {
//$.each(data, function(i, item) {
// // Add the message to the page.
// $('#chartDataLog').append('<li><strong>' + htmlEncode(item.QueueName)
// + '</strong>: ' + htmlEncode(item.Length) + '</li>');
//});
// set up the updating of the chart.
var series = chart.series[0];
$.each(data, function (i, item) {
if (item.QueueName == "Queue A") {
var x = Date.parse(item.Date),
y = item.Length;
series.addPoint([x, y], true, false);
}
});
};
However, I see the graph but not the points.
The strange part is the series data points are there:
Anyone know why HighCharts is not rendering the points?
Thanks, Bill N

I have to thank my good friend and co developer for figuring this out. He is a smarter and braver man than me. :) He went to the highcharts source and found that the highcharts breaks if you add to the graph series before the initial animation is completed. The animation is why the clip-rect is zero-width (it animates from zero to full width over 1s when you first create the chart). You end up adding a point to the series before this animation even really starts. This kills the animation but it doesn’t fix the width of the clip-rect. The fix is to add animation is false for the series.
series: [{ name: 'Processing Queues', data: [], animation: false }]

It looks like you are not defining what your chart.series is until it is created. The line in your ajax is as follows and its not waiting for DOM ready:
var series = chart.series[0];
But you do not define chart until $(document).ready(function () {.... Try keeping your chart object in scope of your ajax.

How to match columns height with spline in Highcharts

I'm using Highcharts to draw a spline. This works good.
I'm using secondary series (columns) for another data.
My problem is: how to set column height to be matched with spline.
As far i've done this: jsfiddle
Columns have height almost i need, but not all.
It is possible at all?
Relevant code:
$('#chart').highcharts({
title: {text: 'Chart'},
chart: {
type: 'spline'
},
xAxis: {
title: {
text: 'X-Axis'
}
},
yAxis: {
title: {
text: 'Y-Axis'
},
labels: {
enabled: false
}
},
series: [{
name: 'Chart',
data: chdata,
marker: {
enabled: false
},
}],
legend: {
enabled: false
}
});
var chartObj = Highcharts.charts[$('#chart').attr('data-highcharts-chart')];
var d = [];
for(var i = 0; i < ldata.length; i++) {
d.push([ldata[i],getYValue(chartObj,0,getClosest(ldata[i],bdata[0]))]);
}
chartObj.addSeries({
type: 'column',
pointWidth: 1,
borderWidth: 0,
data: d
});
I've tried even with plotLines, but it have height of whole chart.
Thanks,
Bartek

Rather than plotting the height of the closest point, try plotting the average height of the points either side of your bar.
You can get even closer if you work out a linear best fit for your bar on the line between the points either side. Something like:
function getY(xVal,points) {
var higher = 0;
var lower=0;
for(var i=0;i<points.length;i++){
if (points[i][0] > xVal) {
higher=i;
lower=i-1;
break;
}
}
return points[lower][1] + ((points[higher][1]-points[lower][1])*(xVal-points[lower][0])/(points[higher][0]-points[lower][0]));
};
http://jsfiddle.net/5h471o3d/

Open Highcharts in modal window

I'm working on a site where I use Highcharts quite heavily for presenting data in charts. I want to user to be able to "zoom" each chart into a modal window for better readability.
I know how to manipulate the chart with its API, but I'm not quite sure how I can clone the chart and refer to the new chart with an variable?
I've done alot of searching, and all I've found is how to open in modal window with Highcharts own modal library, but I'm using a modal library called Lightview.

I have got this working using jQuery modal panel.
On click of original chart I am calling a javascript function popupGraph which will create a new highchart by merging the options of the existing highchart. On close event of modalPanel I am destroying the highchart that we have created for popup.
Hope this helps..
Code for actual chart that I show in small size.
trackingChart = new Highcharts.Chart({
chart: {
renderTo: 'container',
type: 'column',
events: {
load: loadChart,
click: function() {
popUpGraph(this);
}
}
},
xAxis: {
categories: []
},
yAxis: {
min: 0,
},
legend: {
layout: 'horizontal',
backgroundColor: '#FFFFFF',
align: 'center',
verticalAlign: 'bottom',
x: 10,
y: 0,
floating: false,
shadow: true
},
tooltip: {
formatter: function() {
return ''+
this.x +': '+ this.y +' points';
}
},
plotOptions: {
column: {
pointPadding: 0,
borderWidth: 0
}
},
exporting: {
enabled: false
},
series: [{
data: []
}, {
data: []
}]
});
Code for function opening modal panel
function dummy() {}
function popUpGraph(existingChart) {
var options = existingChart.options;
var popupChart = new Highcharts.Chart(Highcharts.merge(options, {
chart: {
renderTo: 'popup_chart',
height:300,
width:700,
zoomType: 'x',
events: {
load: dummy,
click: dummy
}
}
}));
$( "#dialog").dialog({
autoOpen: false,
height: 350,
width: 750,
modal: true,
show:'blind',
close: function(event, ui) { popupChart.destroy(); }
});
$("#dialog").dialog("open");
}

You can get the new range by the selection event and then get the respective position from the chart serie.
See my example.
http://jsfiddle.net/ricardolohmann/sZMFh/
So, if you want to show it inside the lightbox you have to change the following code:
chart2 = new Highcharts.StockChart({
chart: {
renderTo: 'container2'
},
series: newSeries
});
To this one, and set the container2 display to none
Lightview.show({ url: 'container2', type: 'inline' });

Further to Santhosh's answer, I added this at the end of popupGraph function to get data loaded up:
$.each(existingChart.series, function (prop, val) {
popupChart.series[prop].setData(val.options.data);
popupChart.series[prop].update(val.options);
});