Chart.JS - Set fixed X and Y axis values in time chart? - javascript

I'm currently attempting to use Chart.JS to create a line graph, displaying brightness percentages (0-100%) of an LED over 24H.
I'm trying to configure the chart to have set X and Y axis scales.
I need the X axis to display every hour (0,1,2,3... 21,22,23,24), and the Y axis to display values up to 100, going up by 10 (0,10,20... 90,100). I'm unsure how to get it to work. So far I've tried "unitStepSize: 1" and "min: 00:00" + "max: 24:00" as below, but these do not work in the way I had hoped. How can I get this graph to display correctly? Here's my code:
var labels = result.map(e => moment(e.x, 'HH:mm'));
var data = result.map(e => +e.y);
var ctx = document.getElementById("chart").getContext('2d');
var chart = new Chart(ctx, {
type: 'line',
data: {
labels: labels,
datasets: [{
label: 'White',
data: data,
borderWidth: 1
}]
},
options: {
scales: {
xAxes: [{
type: 'time',
time: {
format: "H:mm",
unit: 'hour',
unitStepSize: '1',
tooltipFormat: "H:mm A",
displayFormats: {
hour: 'H',
min: '00:00',
max: '24:00',
}
}
}]
},
}
});```

under options / scale try something like this: --> see yAxes
options: {
responsive: true,
legend: {
position: 'bottom',
},
hover: {
mode: 'label'
},
scales: {
xAxes: [{
display: true,
scaleLabel: {
display: true,
labelString: 'Month'
}
}],
yAxes: [{
display: true,
ticks: {
beginAtZero: true,
steps: 10,
stepValue: 5,
max: 100
}
}]
...
}

Related

Chart.js - Prevent two bars merging as one bar when dates are the same and y values are different

Chart.js v3.2.1
Background: 2 datasets that form a stacked bar chart, x axis is timeseries and y axis is linear.
I have an issue where two bars merge as one bar when the dates are the same. I don't mind the x tick label merging as one date, but the actual bars I would like to keep separate.
My chart configuration:
var myChart = new Chart(ctx, {
type: 'bar',
data: {
datasets: chartDatasets
},
options: {
responsive: true,
maintainAspectRatio: false,
scales: {
x: {
stacked: true,
offset: true,
type: 'timeseries',
time: {
parser: 'YYYY-MM-DD',
tooltipFormat: 'll',
unit: 'day',
displayFormats: {
day: 'MMM D'
},
},
ticks: {
source: 'data',
align: 'center',
},
grid: {
drawOnChartArea: false
},
},
y: {
stacked: true,
type: 'linear',
ticks: {
beginAtZero: true
},
title: {
display: true,
text: 'kg Dry Matter / ha',
font: {
weight: "bold"
}
}
}
}
}
});
I have created a JSFiddle to duplicate the problem.
https://jsfiddle.net/kharrisson/pc359Lg4/10/
In the first dataset provided to the chart, there are 2 "May 18" records with different y values.
Why have they merged into one bar? I am unsure if this is a bug, or if there is a config setting I need to set.

ChartJS Scatter plot cuts highest and lowest points in half

When plotting a time scatter plot by category (x-axis = time, y-axis = category) the points at the top and the bottom of the graph get cut in half:
Is there are way to solve this problem?
I use ChartJS with Angular 6 and the ng2-charts wrapper. This is my Options Object:
public scatterChartOptions: ChartOptions = {
responsive: true,
maintainAspectRatio: false,
tooltips: {
enabled: true
},
legend: {
display: false
},
scales: {
xAxes: [{
type: 'time',
time: {
unit: 'hour',
min: this.minDate.toISOString(),
max: this.maxDate.toISOString()
},
display: true,
ticks:{
padding: 50
}
}],
yAxes: [{
display: true,
type: 'category',
gridLines: {
display:true,
},
}],
}
};

Chart.js hours scale show day switch

I have an array of date for 2 days and I would like to show only hours. No problem for that.
But since we have 2 days, there is no way to see the day switch in the graph. Is there a way to have hours and then a tick with the day when we are switching ?
Something like that :
Thanks !
var labels = ['2018-12-20 14:00', '2018-12-20 15:00', '2018-12-20 16:00', '2018-12-20 17:00', '2018-12-20 18:00', '2018-12-20 19:00', '2018-12-20 23:00', '2018-12-21 02:00', '2018-12-21 03:00', '2018-12-21 04:00', '2018-12-21 05:00', '2018-12-21 10:00'];
var data = [256,24,14,12,154,123,23,254,145,123,11,255];
var ctx = document.getElementById("myChart").getContext('2d');
var myChart = new Chart(ctx, {
type: 'line',
data: {
labels: labels,
datasets: [{
label: 'Tickets selling',
data: data,
borderWidth: 1
}]
},
options: {
scales: {
xAxes: [{
ticks: {
autoSkip: true,
maxTicksLimit: 20,
maxRotation: 0,
},
type: 'time',
time: {
unit: 'hour',
displayFormats: {
hour: 'HH:mm'
}
}
}]
},
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.23.0/moment.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.3/Chart.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<canvas id="myChart"></canvas>
This can be done using the major ticks option in chartjs.
scales: {
xAxes: [{
type: 'time',
time: {
unit: 'hour',
stepSize: 3, // I'm using 3 hour intervals here
tooltipFormat: 'HH:mm',
},
ticks: {
major: {
enabled: true, // <-- This is the key line
fontStyle: 'bold', //You can also style these values differently
fontSize: 14 //You can also style these values differently
},
},
}]
}
This produces an x axis like the follwong

Chartjs last label not shown

[UPDATE] The question seems to be solved (see comments). I will update the answer as soon as i am sure about it
I am trying to achieve a weather chart using chartjs library.
The chart will always have the weather date of the first day of the month and in addition to that one value in between (makes 24 values).
I want all "first day of the month" labels to be shown (with the corresponding gridline), the other data point in between should not be shown (or at least with no gridline).
The Problem now, somehow the last (12th) label is not gonna be shown and I have no idea why. The result looks like that:
My javascript code is that
var ctx = document.getElementById('canvas').getContext('2d');
var myChart = new Chart(ctx, {
type: 'line',
data: {
labels: [
"01","","02","","03","","04", "","05","","06","","07","","08","","09","","10","","11", "","12",""
],
datasets: [{
label: 'Temperature [°C]',
data: [
1,2,3,4,5,6,7,8,9,1,2,3,4,5,6,7,8,9,1,2,3,4,5,6
],
borderColor: "rgb(0, 182, 206)",
pointRadius: 1,
backgroundColor: "rgba(0, 182, 206,0.4)"
}]
},
options: {
responsive: true,
maintainAspectRatio: false,
legend:{
display:false // Suppress interactive legend
},
scales: {
xAxes: [{
scaleLabel: {
display: false,
labelString: 'Month'
} ,
afterTickToLabelConversion: function(data){
var xLabels = data.ticks;
xLabels.forEach(function (labels, i) {
if (xLabels[i].length == 0){
xLabels[i] = '';
}
});
},
ticks: {
//maxRotation: 0,
//minRotation: 0,
autoSkip: true,
maxTicksLimit: 12
}
}],
yAxes: [{
scaleLabel: {
display: true,
labelString: 'Temperature [°C]'
},
ticks: {
beginAtZero: true
}
}]
}
}
});
Do you have some ideas?

chartjs not drawing with formated time for x-axis

I am trying to draw a line chart with time x-axis. But chart is giving me this error. I want to print the time in a certain format 'hh:mm:ss' but looks like this format is causing some issue. When i send hardcoded labels the chart is drawn correctly.
Chart.min.js:14 Uncaught TypeError: Cannot read property 'call' of undefined
This is my call stack
This is my code
var timeFormat = 'h:mm:ss a';
function newDate(days) {
//return moment().add(days, 'd').toDate();
return moment().add(days, 'm').format(timeFormat);
}
function DrawTrendTempChart() {
var temp_data_trend = {
labels: [newDate(0), newDate(10), newDate(20), newDate(30), newDate(40), newDate(50), newDate(60)], // Date Objects,
datasets: [{
lineTension: 0,
label: 'Trend',
data: [1, 2, 3, 4, 5, 6, 7],
pointRadius: 2,
backgroundColor: ['transparent'],
borderColor: [OrangeRGB],
borderWidth: liveDataLineWidth,
//fill: false,
//borderDash: [5, 5],
}]
}
var temp_options_trend = {
scales: {
xAxes: [{
type: "time",
time: {
format: timeFormat,
tooltipFormat: timeFormat,
unit: 'minute',
unitStepSize: 20,
},
scaleLabel: {
display: true,
labelString: 'Date'
}
}, ],
yAxes: [{
scaleLabel: {
display: true,
labelString: 'value'
},
ticks: {
autoSkip: false
}
}]
},
legend: { display: true },
tooltips: { enabled: true },
showTooltips: true,
responsive: true,
title: {
display: true,
text: "Trend Chart"
}
}
var ctx = document.getElementById("sensorDataTrend").getContext("2d");
myChart = new Chart(ctx, {
type: 'line',
data: temp_data_trend,
options: temp_options_trend
});
}

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