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I have some time based data I want a graphical representation of, and was hoping to use Chartjs to plot this.
The data looks something like the following:
Time State
--------------
7am up
9am down
10.45am out
17.35 up
Also, each "state" will have its own color, so I would use this as a bar color when using a bar graph
up = red
down = yellow
out = green
The end result I am after is a simple one row bar like the following...
I thought I may be able to use a Chartjs horizontal stacked bar chart (https://www.chartjs.org/docs/latest/charts/bar.html#horizontal-bar-chart) to do this somehow, but I just can't work out how to get this working.
Some (not working) experimental code is as follows:
private createChart(): void {
if (this.chart !== undefined) {
return;
}
Chart.register(BarController, PointElement, Tooltip, Legend, TimeScale, LinearScale, CategoryScale, LinearScale, BarElement);
const options: ChartOptions = {
plugins: {
legend: {
display: false,
},
title: {
display: false,
},
},
indexAxis: 'y',
responsive: true,
maintainAspectRatio: false,
scales: {
y: {
stacked: true,
type: 'time',
display: true,
// position: 'bottom',
time: {
unit: 'minute',
displayFormats: {
minute: 'h:mm a'
}
}
},
x: {
stacked: false,
}
}
};
this.chart = new Chart(this.canvasRef.nativeElement, {
type: 'bar',
data: this.chartData,
options
});
this.chart.config.options.scales.y.min = new Date('2023-02-13T06:19:31.842Z').getTime();
const labels = [
'up',
'down'
// 'Dataset 2'
];
const d1 = new Date('2023-02-13T06:20:32.842Z').getTime();
const d2 = new Date('2023-02-13T06:21:33.842Z').getTime();
this.chartData = {
labels,
datasets: [{
label: 'up',
data: [{x: 10, y: d1}],
backgroundColor: 'red',
},
{
label: 'down',
data: [{x: 20, y: d2}],
backgroundColor: 'green',
}
]
};
this.chart.update();
}
In the above I have tried various combinations of labels, x values, y values, data shapes, but I only even get an empty graph.
Perhaps this is not really possible (I am trying to use the wrong component).
How can I achieve this using chartjs?
Update
Using example from #winner_joiner below, I have put a copy of it at plunkr and have tried to use the time in the x axis, but can see it is still not plotting the bars using the dates as the length
Well your code basically works, here a slightly modified version of your code.
After your comments and updated question, I reworke the example (seen below). Although it is possible to do with chart.js the question is, maybe for this specific task a different library or solution would be better/more convenient.
Update Chart, with some similar values from your question:
(I'm using here momentjs, since it is recommend usually needed form date/time actions in chartjs, as mentioned in the documentation)
const d0 = moment.duration('07:00:00').asMinutes();
const d1 = moment.duration('09:00:00').asMinutes();
const d2 = moment.duration('10:45:00').asMinutes();
const d3 = moment.duration('17:35:00').asMinutes();
const d4 = moment.duration('19:00:00').asMinutes();
let values = [d0, d1, d2, d3, d4];
let data = {
labels: [''],
datasets: [{
label: 'up',
axis: 'y',
data: [d1],
backgroundColor: 'red',
},{
label: 'down',
axis: 'y',
data: [d2],
backgroundColor: 'yellow',
},{
label: 'out',
axis: 'y',
data: [d3],
backgroundColor: 'green',
},{
label: 'up',
axis: 'y',
data: [d4],
backgroundColor: 'red',
}
]
};
const config = {
data,
type: 'bar',
options:{
plugins: {
tooltip: {
mode: 'dataset',
callbacks: {
label: function(item){
return moment().startOf('day').add({ minute: item.raw}).format('HH:mm');
}
}
},
legend: {
display: false,
},
title: {
display: false,
},
},
indexAxis: 'y',
responsive: true,
maintainAspectRatio: false,
scales: {
x: {
min: d0,
ticks: {
callback: function(value, index, ticks) {
return moment().startOf('day').add({ minute: value}).format('HH:mm');
}
},
afterBuildTicks: axis => axis.ticks = values.map(v => ({ value: v }))
},
y: {
stacked: true
},
}
}};
new Chart(document.getElementById("chart"), config);
<script src="//cdn.jsdelivr.net/npm/chart.js"></script>
<script src="//cdn.jsdelivr.net/npm/moment#^2"></script>
<script src="//cdn.jsdelivr.net/npm/chartjs-adapter-moment#^1"></script>
<div class="chart" style="height:184px; width:350px;">
<canvas id="chart" ></canvas>
</div>
I have this chart:
...which is displaying exactly how I want it to with one exception... The data in the bars is for between the two times in the x axis... so all the labels need shifting to lie on the grid lines, not between them as default for a bar chart. So the red and blue bar is data between 8:00 and 9:00. I hope I've explained that clearly enough.
I'm trawling through the Chart.js docs and it just doesn't seem like this is possible! I know I could change my labels to be, for example, 8pm - 9pm, but that seems a much more visually clunky way of doing it. Is there a way anyone know of achieving this? Ideally there would be another '12am' on the last vertical grid line too.
You can draw the tick lables at the desired position directly on to the canvas using the Plugin Core API. It offers number of hooks that may be used for performing custom code. In below code snippet, I use the afterDraw hook to draw my own labels on the xAxis.
const hours = ['00', '01', '02', '03', '04', '05', '06'];
const values = [0, 0, 0, 0, 10, 6, 0];
const chart = new Chart(document.getElementById('myChart'), {
type: 'bar',
plugins: [{
afterDraw: chart => {
var xAxis = chart.scales['x-axis-0'];
var tickDistance = xAxis.width / (xAxis.ticks.length - 1);
xAxis.ticks.forEach((value, index) => {
if (index > 0) {
var x = -tickDistance + tickDistance * 0.66 + tickDistance * index;
var y = chart.height - 10;
chart.ctx.save();
chart.ctx.fillText(value == '0am' ? '12am' : value, x, y);
chart.ctx.restore();
}
});
}
}],
data: {
labels: hours,
datasets: [{
label: 'Dataset 1',
data: values,
categoryPercentage: 0.99,
barPercentage: 0.99,
backgroundColor: 'blue'
}]
},
options: {
responsive: true,
legend: {
display: false
},
scales: {
xAxes: [{
type: 'time',
time: {
parser: 'HH',
unit: 'hour',
displayFormats: {
hour: 'Ha'
},
tooltipFormat: 'Ha'
},
gridLines: {
offsetGridLines: true
},
ticks: {
min: moment(hours[0], 'HH').subtract(1, 'hours'),
fontColor: 'white'
}
}]
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.24.0/moment.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.min.js"></script>
<canvas id="myChart" height="90"></canvas>
I'm trying to use chart.js to create a bar chart that shows the number of ad impressions in an ad buy by publication. The desired chart would show a bar for each publication representing the number of impressions for the ad on that website.
I thought that this needs to happen as multiple datasets, one for each publication, where each dataset contains one data point. Here's the code I'm using for this approach:
var chartData_webbanner_300x600 = {
labels: ["Publication 1", "Publication 2"],
datasets: [
{
label: "Publication 1",
backgroundColor: "#971317",
data: [30000]
},
{
label: "Publication 2",
backgroundColor: "#0b72ba",
data: [40000]
},
]
};
window.onload = function() {
var ctx_webbanner_300x600 = document.getElementById('chart_webbanner_300x600').getContext('2d');
window.myBar = new Chart(ctx_webbanner_300x600, {
type: 'bar',
data: chartData_webbanner_300x600,
options: {
title: {
display: true,
text: 'Web Banner Impressions'
},
responsive: true,
}
});
}; //window.onload = function()
The resulting chart only shows one bar. Here's a screenshot:
I also tried this as a single dataset, but had no luck there. This is the approach I tried with that:
var chartData_webbanner_300x600 = {
labels: ["Total Impressions"],
datasets: [
{
label: ["Publication 1", "Publication 2"],
backgroundColor: ["#971317","#0b72ba"],
data: [30000,40000]
}
]
};
window.onload = function() {
var ctx_webbanner_300x600 = document.getElementById('chart_webbanner_300x600').getContext('2d');
window.myBar = new Chart(ctx_webbanner_300x600, {
type: 'bar',
data: chartData_webbanner_300x600,
options: {
title: {
display: true,
text: 'Web Banner Impressions'
},
responsive: true,
}
});
}; //window.onload = function()
Here's how that is displaying (with no bars):
Please let me know if you have any ideas on what I'm doing wrong. Thank you for taking the time to help!
I was able to get it working with this code:
var graphData = {
labels: ['Publication 1', 'Publication 2'],
datasets: [{
label: 'Impressions',
data: [30000, 40000],
backgroundColor: [
"#971317",
"#0b72ba"
],
}, ]
};
var ctx_webbanner_300x600 = document.getElementById('chart_webbanner_300x600').getContext('2d');
var chr = new Chart(ctx_webbanner_300x600, {
data: graphData,
type: 'bar',
options: {
scales: {
yAxes: [{
display: true,
ticks: {
beginAtZero: true // minimum value will be 0.
}
}]
}
}
});
This is based on what I found here Setting specific color per label in chart.js and here How to set max and min value for Y axis - which overcame a problem where the scale was starting at the lowest value in my data set.
Input data
Engine,Car,Brand,Efficiency
ABC212,Toyota Corolla,Toyota,1.95
ABC212,Toyota Yaris,Toyota,1.94
ABC212,Totyota Etios,Toyota,1.93
ABC212,Honda City,Honda,1.93
ABC212A,Honda Brio,Honda,1.91
DEF311,Toyota Camry,Toyota,1.90
DEF310,Toyota Prius,Toyota,1.82
DEF310,Ford Explorer,Ford,1.85
DEF310,Ford Endeavour,Ford,1.83
DEF305,Ford Fugo,Ford,1.79
With data like above, I need to create a chart in ChartJs with multi-level x-axes. An expected output created using MS excel pivot chart is as below. Here the efficiency of each model is plotted as a bar. Bars in each group is sorted in the descending order of the efficiency value. How should I create the data for this kind of chart ?
I have made such graph in my POC , where I used :
data: {
labels: ["ABC212", "ABC212A",...],
datasets: [
{
label: "ABC212",
data: [val1, val2,....]
}, {
label: "ABC212A",
data: [val3, val4,...]
}
]
}
Without being confident that this is the simplest solution, I provide some example where I use a second axis, containing labels for the groups, but in a scaled-up array, for correct alignment.
The only problem is that if you enable rotation for the group maxRotation>0, the text will always be rotated, since (due to scaling) it is bound to a very small area.
https://jsfiddle.net/h6z4apvo/
var myData = [
["ABC212","Toyota Corolla","Toyota",1.95],
["ABC212","Toyota Yaris","Toyota",1.94],
["ABC212","Totyota Etios","Toyota",1.93],
["ABC212","Honda City","Honda",1.93],
["ABC212A","Honda Brio","Honda",1.91],
["DEF311","Toyota Camry","Toyota",1.90],
["DEF310","Toyota Prius","Toyota",1.82],
["DEF310","Ford Explorer","Ford",1.85],
["DEF310","Ford Endeavour","Ford",1.83],
["DEF305","Ford Fugo","Ford",1.79]
];
/*Calculates group labels to a scaled array so that they can align better*/
function calculateGroupLabels(data){
const scaleFactor=100;
var labels = _(data)
.groupBy((elem)=>elem[0])
.map((entriesOnSameGroup, key)=>{
var newSize = entriesOnSameGroup.length*scaleFactor;
var newArray = new Array(newSize);
newArray[0]="";
newArray[newArray.length-1]="";
newArray[parseInt((newArray.length-1)/2)]=key;
return newArray;
}).flatten().value()
return labels;
}
var labels = calculateGroupLabels(myData);
var ctx = $("#c");
var myChart = new Chart(ctx, {
type: 'bar',
data: {
datasets: [{
label: '# of Votes',
xAxisID:'modelAxis',
data: myData.map((entry)=>entry[3])
}]
},
options:{
scales:{
xAxes:[
{
id:'modelAxis',
type:"category",
ticks:{
//maxRotation:0,
autoSkip: false,
callback:function(label, x2, x3, x4){
console.log("modelAxis", label, x2, x3, x4)
return label;
}
},
labels:myData.map((entry=>entry[1]))
},
{
id:'groupAxis',
type:"category",
gridLines: {
drawOnChartArea: false,
},
ticks:{
padding:0,
maxRotation:0,
autoSkip: false,
callback:function(label){
return label;
}
},
labels:labels
}],
yAxes:[{
ticks:{
beginAtZero:true
}
}]
}
}
});
I would like to update specific column background colour but I couldn't do this. Seem like it is very easy but all the solution I tried out from google doesn't work. The code is as below.
var ctx = document.getElementById("myChart");
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels : ["A","B","C","D","E"],
datasets: [{
data : [<?php echo $graph_data;?>],
backgroundColor: "rgba(0,0,220,0.5)",
borderColor: "rgba(0,0,220,1)",
borderWidth: 2
}]
}
});
//I would like to achieve something like this, let's say change the first and second bar's background color
myChart.datasets[0].bars[0].fillColor = "rgba(220,0,0,0.5)";
myChart.datasets[0].bars[1].fillColor = "rgba(220,0,0,0.5)";
myChart.update();
I had an old code which run succesfully under version 1.0.1-beta.4, but now I world like to use the latest version 2.5.0, and then I faced this issue.
Thanks for any helps!
You can just pass an array to the backgroundColor bar chart dataset property (instead of a single color) where the position in the array maps to the position in the data array.
For example, if you have 3 bars and want all 3 to be a different color, just pass an array to backgroundColor where all 3 elements have a different color value.
var ctx = document.getElementById("canvas").getContext("2d");
var myBar = new Chart(ctx, {
type: 'bar',
data: {
labels: ["Car", "Bike", "Walking"],
datasets: [{
label: 'Fuel',
backgroundColor: [
chartColors.red,
chartColors.blue,
chartColors.yellow],
data: [
randomScalingFactor(),
randomScalingFactor(),
randomScalingFactor(),
]
}]
},
options: {
title: {
display: true,
text: "Chart.js - Different Bar Colors"
},
tooltips: {
mode: 'index',
intersect: false
},
legend: {
display: false,
},
responsive: true,
}
});
Here is a codepen example demonstrating this.