chart.js plotting timeseries - javascript

Attempting to pass through data from django to a webpage to render a responsive chart. The data are being passed correctly to js, but I am driving myself crazy trying to understand why charts.js is throwing an error.
I have hardcoded some data for example:
function setLineChart() {
var ctx = document.getElementById("myLineChart").getContext('2d');
var dat_1 = {
label: 'things',
borderColor: 'blue',
data: [
{t: new Date("04/01/2020"), y: 310},
{t: new Date("04/02/2020"), y: 315},
{t: new Date("04/03/2020"), y: 320},
]
};
var myLineChart = new Chart(ctx, {
type: 'line',
data: {
datasets: [dat_1]
},
options: {
scales: {
xAxes: [{
type: 'time',
time: {
unit: 'day'
},
}],
yAxes: [{
ticks: {
beginAtZero: true
}
}]
}
}
})
}
<canvas id="myLineChart" width="600" height="600"></canvas>
And this returns a Uncaught TypeError: Cannot read property 'skip' of undefined error that I can't debug. setLineChart() gets called as part of an ajax response on a form update. When I comment out the options section, it does render a chart, but misses off the last data point, and has undefined as the x-axis marker.
Any help would be appreciated.

Chart.js internally uses Moment.js for the functionality of the time axis. Therefore you should use the bundled version of Chart.js that includes Moment.js in a single file.
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.bundle.min.js"></script>
This will solve your problem as the following amended code snippet illustrates.
var ctx = document.getElementById("myLineChart").getContext('2d');
var dat_1 = {
label: 'things',
borderColor: 'blue',
data: [
{ t: new Date("04/01/2020"), y: 310 },
{ t: new Date("04/02/2020"), y: 315 },
{ t: new Date("04/03/2020"), y: 320 },
]
};
var myLineChart = new Chart(ctx, {
type: 'line',
data: {
datasets: [dat_1]
},
options: {
scales: {
xAxes: [{
type: 'time',
time: {
unit: 'day'
},
}],
yAxes: [{
ticks: {
beginAtZero: true
}
}]
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.bundle.min.js"></script>
<canvas id="myLineChart" height="90"></canvas>

Related

Counting string to plot a graph using chart.js and angular

I am trying to create a bar chart in angular using chart.js and angular.
I want to display the disaters vs area. with the type of disaster ( earthquake, hurricane, storm...etc) on the x-axis and area (as in location) on the y-axis.
However, the area data is string and does not work when trying to plot a bar graph as it requires numbers.
I am reading the data as follows:
ngOnInit(): void {
this.chartService.noOfEqu().subscribe((res) => {
let area = res.map((res) => res.area);
let disaster = res.map((res) => res.disasterNature);
new Chart('disasterCanvas', {
type: 'bar',
data: {
labels: disaster,
datasets: [
{
data: area,
label: 'area',
backgroundColor: '#A121D5',
},
],
},
options: {
plugins: {
legend: {
display: true,
},
},
scales: {
x: {
ticks: {
display: true,
},
},
y: {
ticks: {
display: true,
},
},
},
},
});
});
}
}
Where let area = res.map((res) => res.area); is the area variable.
I want to know what is the best way to structure the data to be entered into the graph.
The disaster data that is logged is:
and the area data :
How can i structure the area such that it counts how much areas that a disaster has occured and plot it on the bar chart?
Thank you in advance...if there is anything i can clarify please let me know in the comments
Also is there another way to display this data besides tallying the string data?
You need to add a labels array to the scale and set the type to category to use string data:
const options = {
type: 'bar',
data: {
labels: ["Earthquake", "Tornade", "Flood"],
datasets: [{
label: '# of Votes',
data: ['Paris', 'Berlin', 'London'],
backgroundColor: 'pink'
}]
},
options: {
scales: {
y: {
type: 'category',
reverse: true,
labels: ['', 'London', 'Paris', 'Berlin']
}
}
}
}
const ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);
<body>
<canvas id="chartJSContainer" width="600" height="400"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.7.1/chart.js"></script>
</body>

Styling problems with Chart.Js

How can I add these styles to my graph? I'm having trouble finding it in the documentation for it, and the other forums aren't very helpful. I am using Flask for the backend, so that's why the data values look like that.
Labels on top of bars
Change font size on both axis
Set y scale as a fixed value (0,8)
<script>
var ctx = document.getElementById('myChart').getContext('2d');
var options = {
scales: {
yAxes: [{
ticks: {
fontSize: 40
}
}]
}
}
var myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: ['Lithium Battery', 'Other Mfg', 'Delivery', 'Tailpipe', 'Fuel Cycle', 'Disposal', 'Total'],
datasets: [{
label: 'ICEV CAR (MTCO2e/Year)',
labels: [
"{{data['battery_icev_car']}}",
"{{data['other_mfg_icev_car']}}",
"{{data['delivery_icev_car']}}",
"{{data['tailpipe_icev_car']}}",
"{{data['fuel_cycle_icev_car']}}",
"{{data['disposal_icev_car']}}",
"{{data['total_icev_car']}}"
],
data: [ /* errors are normal, fixes when server ru
[0, {{data['y1_icev']}}],
[{{data['y1_icev']}}, {{data['y2_icev']}}],
[{{data['y2_icev']}}, {{data['y3_icev']}}],
[{{data['y3_icev']}}, {{data['y4_icev']}}],
[{{data['y4_icev']}}, {{data['y5_icev']}}],
[{{data['y5_icev']}}, {{data['y6_icev']}}],
[0, {{data['y6_icev']}}]
],
backgroundColor: [
'rgba(0,0,0,0.9)'
],
borderColor: [
'rgba(0,0,0,1)'
],
borderWidth: 1,
borderSkipped: false
}]
},
options: {
responsive: true,
plugins: {
legend: {
labels: {
// This doesn't work on axis
font: {
size: 20
}
}
}
},
y: {
beginAtZero: true
}
}
});
</script> </script>
Since your config is not working I assume you are using V3, in which case the solution is as followed:
For point one you need to use an external plugin, you can write your own or use the datalabels plugin
For your second problem you need to style it as a font object as told in the documentation like so:
options: {
scales: {
y:{
ticks:{
font:{
size: 50
}
}
}
}
}
For your last part you can set the stepSize to 0.8

How to change font weight of footer in tooltips in Chart JS

I am trying to change the font weight of footer in tooltips in Chart JS. According to this link (https://www.chartjs.org/docs/latest/configuration/tooltip.html#tooltip-configuration), footerFont seems to be the one to control this but I could not quite get it to work
My code:
options: {
tooltips:{
footerFont: {weight: 'normal'},
callbacks: {
footer: function(tooltipItem, data) {
return 'some text'
}
}
},
}
Fiddle: https://jsfiddle.net/dqdqdq/yp47oL9t/10/ . The footer is still bold when we hover any bubbles.
You are looking at the documentation of chart.js version 3 which has some major changes from version 2, if you take the version 2 docs: https://www.chartjs.org/docs/2.7.1/configuration/tooltip.html you can see that the property is called a bit different and also just accepts a string
Working sample:
var ctx = document.getElementById('myChart').getContext('2d');
var myChart = new Chart(ctx, {
type: 'bubble',
data: {
datasets: [{
label: 'Top',
data: [{
x: 110,
y: 0,
r: 10,
name: "Performance"
}],
backgroundColor: "rgba(153,255,51,0.6)"
},
{
label: 'Average',
data: [{
x: 75,
y: 0,
r: 10,
name: "Performance"
}],
backgroundColor: "rgba(153,155,51,0.6)"
},
]
},
pointDot: true,
options: {
tooltips: {
footerFontStyle: 'normal',
callbacks: {
footer: function(tooltipItem, data) {
return 'some text'
}
}
},
}
});
<canvas id="myChart"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.1/Chart.bundle.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/chartjs-plugin-datalabels#0.2.0/dist/chartjs-plugin-datalabels.min.js"></script>

Chart.js - Timeline

I am trying to display dates on xAxes with Chart.js
I tried this with 2 dates but it shows nothing.
Probably something I did wrong with the labels or date format.
<canvas id="graph"></canvas>
<script>
var ctx = document.getElementById('graph').getContext('2d');
var myChart = new Chart(ctx, {
type: 'line',
data: {
labels: ["2013-02-08", "2013-02-10"],
datasets: [{
label: "Something",
data: [{
x: "2013-02-08",
y: 1
}, {
x: "2013-02-10",
y: 10
}]
}]
},
options: {
scales: {
xAxes: [{
type: 'time',
time: {
unit: 'day'
}
}]
}
}
});
</script>
Need help :)
Your code looks fine except that you don't need to define data.labels since the data in your dataset is defined as individual points through objects containing x and y properties.
Chart.js internally uses Moment.js for the functionality of the time axis. Therefore you should use the bundled version of Chart.js that includes Moment.js in a single file.
var ctx = document.getElementById('graph').getContext('2d');
var myChart = new Chart(ctx, {
type: 'line',
data: {
datasets: [{
label: "Something",
data: [
{ x: "2013-02-08", y: 1 },
{ x: "2013-02-10", y: 10 }
]
}]
},
options: {
scales: {
xAxes: [{
type: 'time',
time: {
unit: 'day'
}
}]
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.bundle.min.js"></script>
<canvas id="graph"></canvas>

Dynamic stacked column in CanvasJS

How can I create a stacked column chart with dynamic data?
For example, I have an external JSON object like:
[
{
id : ‘ID123’,
occurrences: [5,6,8],
description: ["Hours spent working", "Hours spent skiing", "Hours spent studying"]
},
{
id : ‘ID456’,
occurrences: [7,2,12],
description: ["Hours spent working", "Hours spent skiing", "Hours spent studying"]
}
]
How do I make it so there would be two stacked columns using the id as the label and the array of occurrences is used to build the stacked column on top of each label?
Edit:
Added representation of how graph should look
I would suggest using chart.js for this as it will be much easier than building it out yourself. Here is a example using the data you provided.
var barChartData = {
labels: ['ID123', 'ID456'],
datasets: [{
label: 'Hours spent working',
backgroundColor: '#FF0000',
data: [
5,
7
]
}, {
label: 'Hours spent skiing',
backgroundColor: '#00FF00',
data: [
6,
2
]
}, {
label: 'Hours spent studying',
backgroundColor: '#0000FF',
data: [
8,
12,
]
}]
};
window.onload = function() {
var ctx = document.getElementById('canvas').getContext('2d');
window.myBar = new Chart(ctx, {
type: 'bar',
data: barChartData,
options: {
title: {
display: true,
text: 'Chart.js Bar Chart - Stacked'
},
tooltips: {
mode: 'index',
intersect: false
},
responsive: true,
scales: {
xAxes: [{
stacked: true,
}],
yAxes: [{
stacked: true
}]
}
}
});
};
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.8.0/Chart.min.js"></script>
<canvas id="canvas"></canvas>

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