I am using Highcharts to automatically plot an array which is output from a sensor and is updated every second or so. The array is x elements long. This particular sensor measures the light intensity at x steps between some min and max wavelengths (that is, it measures the intensity at increments of (max-min)/x--in my case this increment is not an integer). I also have a static data set that is plotted on the same axes with the same x-axis requirements.
I am able to successfully graph this data dynamically, but the x-axis scale is wrong. Instead of ranging from min to max, Highcharts defaults to a range of min to min+x. I'd like to change the x-axis increment so that the scaling is correct.
Can a min, max, and number of data points or step be defined to generate the x-axis? Or is there a way to define the x- and y-axis values as individual arrays that are plotted against each other? Some other way? I have done lots of searching and experimenting but have come up short.
The relevant snippet of my code is below.
function showData(result) { // 'result' is an array that comes from the sensor
var numbers = int(split(resultString, ","));
chart.series[1].setData(numbers);
socket.send('a'); // send a byte to tell it to start sending new data
loop++; //increase loop every time the server receives data
chart.setTitle({ text: 'Spectrum, reading #' + loop });
} //showData
$(function () {
chart = new Highcharts.Chart({
chart: {
renderTo: 'container',
type: 'area',
load: function() {
chart = this;
showData();
}
},
title: {
text: 'Spectrum, reading 0'
},
xAxis: {
title: {
text: 'Wavelength [nm]',
allowDecimals: false,
},
},
yAxis: {
title: {
text: ''
},
},
tooltip: {
pointFormat: '{point.x}'
},
plotOptions: {
area: {
pointStart: 340,
marker: {
enabled: false,
symbol: 'circle',
radius: 2,
states: {
hover: {
enabled: true
}
}
}
}
},
series: [{
name: '404 nm laser spectrum',
data: [130,130,114,113,113,116,112,111,112,112,115,113,113,115,
112,114,113,113,114,115,113,114,113,114,115,115,117,119,124,
136,145,164,190,217,252,363,482,491,417,285,188,156,140,132,
127,122,117,118,117,115,116,115,116,118,116,116,117,116,117,
116,113,117,114,113,115,112,116,114,114,116,114,114,116,113,
116,115,114,115,115,114,115,115,115,116,114,115,116,114,118,
114,116,116,115,118,114,113,117,113,116,116,115,116,115,115,
115,114,117,116,117,118,120,118,122,119,128,127,130,134,136,
138,140,137,139,134,136,134,132,133,134,131,132,130,130,131,
128,128,131,129,131,131,134,136,134,140,139,137,143,140,138,
141,136,134,132,127,126,126,123,123,118,119,122,118,120,117,
116,118,116,118,116,115,117,116,115,116,115,115,116,114,119,
113,114,116,115,116,114,114,116,116,113,117,116,114,118,112,
115,114,113,116,115,114,115,113,116,114,114,116,115,115,114,
112,114,114,113,114,115,113,117,114,115,112,114,114,113,115,
114,114,115,113,112,115,112,113,115,112,116,113,113,115,116,
113,116,113,115,113,114,115,115,114,116,114,116,113,116,117,
113,115,116,115,117,115,114,117,113,115,118,114,116,115,115,
116,114,113,116,114,117,115,114,117,115,114,115,116,116,116,
117,117,114,0],
color: '#36D39F'
}, {
name: 'Current measured spectrum',
data: numbers,
color: '#4A235A'
}]
});
});
EDIT: here's a demo showing how mine currently functions: https://jsfiddle.net/bgzgc1d9/2/. The x-axis should range from 340 to 850 with 288 data points evenly spaced on this interval
I am trying to plot a categorical multi axis column chart of rankings. The number 1 ranking should be the tallest column and lowest ranking the shortest.
Essentially I would like the height of the bar to be it's reciprocal.
It is very close to:
var player_name_array = ["Aaron Rodgers", "Andrew Luck", "Drew Brees", "Russell Wilson", "Peyton Manning", "Ryan Tannehill", "Tony Romo", "Matt Ryan", "Cam Newton", "Ben Roethlisberger", "Eli Manning", "Philip Rivers", "Colin Kaepernick", "Teddy Bridgewater", "Marcus Mariota", "Matthew Stafford", "Robert Griffin III", "Joe Flacco", "Jay Cutler", "Sam Bradford"];
var series_array = [{"name":"espn_ranking","data":[38,33,63,64,67,95,75,85,96,76,999,999,999,999,999,999,999,999,999,999]}];
rankings_chart = new Highcharts.Chart({
chart: {
renderTo:'rankings_chart',
type: 'column'
},
title: {
text: 'Draft Rankings'
},
subtitle: {
text: 'Source: The Internet'
},
xAxis: {
categories: player_name_array,
crosshair: true
},
yAxis: {
type: 'logarithmic',
//reversed: true,
title: {
text: 'Draft Rankings'
}
},
tooltip: {
headerFormat: '<span style="font-size:14px"><b>{point.key}</b></span><table>',
pointFormat: '<tr><td style="color:{series.color};padding:0">{series.name}: </td>' +
'<td style="padding:0"><b>{point.y}</b></td></tr>',
footerFormat: '</table>',
shared: true,
useHTML: true
},
plotOptions: {
series: {
stacking:'normal',
},
column: {
pointPadding: 0.2,
borderWidth: 0
}
},
rangeSelector: {
selected: 1
},
series: series_array
});
<script src="https://code.highcharts.com/highcharts.js"></script>
<div id="rankings_chart" ></div>
The problem with this is the columns come down from the top and ranking of 1 is still the smallest column.
Is there any way to add a function for the height of each column?
Set up your data to be the inverse of the player ranking:
var rankings = [38,33,63,64,67,95,75,85,96,76,999,999,999,999,999,999,999,999,999,999]
var inv_rankings = [];
for (i = 0; i < rankings.length; i++) {
inv_rankings[i] = 1 / rankings[i]
}
Set your Highcharts data to be your inverse ranking:
series: {
name: "espn_ranking",
data: inv_rankings
}
Use a formatter for the data labels and tooltip to return the reciprocal of the reciprocal (i.e. the original value):
plotOptions: {
series: {
dataLabels: {
enabled: true,
formatter: function() {
return 1 / this.y;
}
}
},
tooltip: {
pointFormatter: function() {
return 1 / this.y;
}
}
}
Working fiddle
This was an interesting and fun puzzle to work out!
I thought the answer by nagyben was an excellent one, and I based my code on their method of inversing the scores to come up with a relative rank.
Here's a working fiddle I created based on that concept, along with several enhancements, which I've shared below: https://jsfiddle.net/brightmatrix/j4ug40qm/
I added a sort function to rank the data in descending order, no matter how the data were arranged in the original two arrays. In order to do this, I first combined both arrays into a single Javascript object.
I changed the format to a column (vertical) chart to a bar (horizontal) chart. This will make the player names more readable for your users.
I updated the tooltip to show the player's rank whenever a user hovers their cursor over a particular bar.
I removed certain chart elements that aren't needed in this kind of chart, such as the legend, gridlines, and axis labels (since you're simply doing a rank, the true value of each bar isn't relevant to the user).
Here's the sort code that I built into this:
// combine both arrays into a single object so we can then sort them by rank
var rankArray = [];
$.each(player_name_array, function(index) {
tempArray = {};
tempArray['name'] = player_name_array[index];
tempArray['y'] = 1 / series_array[index];
rankArray.push(tempArray);
});
// sort the objects by rank (the "y" value) in descending order (due to the inverse)
// see accepted answer by Stobor at:
// http://stackoverflow.com/questions/979256/sorting-an-array-of-javascript-objects
rankArray.sort(function(a, b) {
return parseFloat(b.y) - parseFloat(a.y);
});
And here's the updated chart options:
rankings_chart = new Highcharts.Chart({
chart: {
renderTo:'rankings_chart',
type: 'bar' // chose a bar vs. column chart so the player names are easier to read
},
title: { text: 'Draft Rankings' },
subtitle: { text: 'Source: The Internet' },
legend: { enabled: false }, // there is no legend needed for this chart
xAxis: {
type: 'category',
tickmarkPlacement: 'on' // place the lines directly on the player's name
},
yAxis: {
// we're measuring by rank, so there's no need for labels, gridlines, or a title
labels: { enabled: false },
title: { enabled: false },
gridLineWidth: 0
},
tooltip: {
pointFormatter: function() {
// show the rank of the player, based on their sort order
return 'ranked #' + parseInt(this.x+1);
}
},
plotOptions: {
bar: {
groupPadding: 0.1,
pointPadding: 0.2,
borderWidth: 0
}
},
series : [{
name : 'Draft Data',
data : rankArray // our array will look like this: [{name: 'NAME', y: 0}, ...]
}]
});
Here's the result:
I hope this has been helpful to you in your chart conversion.
Since you seem to already have set an upper limit of 999 for your data, i would suggest simply plotting 1000-x.
One way to do that is to let highcharts do the math in a function for the series:
series : [{
name : 'Draft Data',
data : (function () {
// generate an array of random data
var data = [];
for (var x = 0;x <= series_array.length; x += 1) {
data.push([
1000-series_array[x];
]);
}
return data;
}())
}]
JSFiddle: http://jsfiddle.net/hmjnz/4/
In this case i would hide the yaxis label and instead put annotations on the columns with the rank.
Alternatively i'd debate whether a column chart is an adequate representation for this type of data.
I have a column chart with two series, one of which I want to go down and the other up, like this:
However both of the series have positive y-values, which I can't change, e.g.
blue = [1746181, 1884428, 2089758, 2222362, 2537431, 2507081, 2443179,
2664537, 3556505, 3680231, 3143062, 2721122, 2229181, 2227768,
2176300, 1329968, 836804, 354784, 90569, 28367, 3878];
grey = [1656154, 1787564, 1981671, 2108575, 2403438, 2366003, 2301402, 2519874,
3360596, 3493473, 3050775, 2759560, 2304444, 2426504, 2568938, 1785638,
1447162, 1005011, 330870, 130632, 21208];
Using highcharts options, is it possible to have a chart like this? The example I used for the screenshot is this jsFiddle if it's useful to anyone, however it has a series with negative values which is not an option for me. Instead my data is more like this fiddle
I would try to use two separate yAxes: http://jsfiddle.net/zares7x9/2/, where one of them is reversed:
yAxis: [{
title: {
text: null
},
top: '5%',
height: '45%',
labels: {
formatter: function () {
return (Math.abs(this.value) / 1000000) + 'M';
}
},
min: 0,
max: 4000000
}, {
title: {
text: null
},
labels: {
formatter: function () {
return (Math.abs(this.value) / 1000000) + 'M';
}
},
offset: 0,
showFirstLabel: false, // hide 0-value
reversed: true, //reverse
top: '50%',
height: '45%',
min: 0,
max: 4000000
}],
Setting top and height allows you to render axes like one. Note, that you need to set for one of the series yAxis: 1, to inform Highcharts which series belongs to which axis.