Hi i am new to canvasjs, my goal is to display temperature sensor real time data using canvas dynamic chart. Code from canvasjs is show below. It generated random number so how do i change following code so that it reads value from csv file?
<!DOCTYPE HTML>
<html>
<head>
<script type="text/javascript">
window.onload = function () {
var dps = []; // dataPoints
var chart = new CanvasJS.Chart("chartContainer",{
title :{
text: "Live Random Data"
},
data: [{
type: "line",
dataPoints: dps
}]
});
var xVal = 0;
var yVal = 100;
var updateInterval = 100;
var dataLength = 500; // number of dataPoints visible at any point
var updateChart = function (count) {
count = count || 1;
// count is number of times loop runs to generate random dataPoints.
for (var j = 0; j < count; j++) {
yVal = yVal + Math.round(5 + Math.random() *(-5-5));
dps.push({
x: xVal,
y: yVal
});
xVal++;
};
if (dps.length > dataLength)
{
dps.shift();
}
chart.render();
};
// generates first set of dataPoints
updateChart(dataLength);
// update chart after specified time.
setInterval(function(){updateChart()}, updateInterval);
}
</script>
<script type="text/javascript" src="https://cdn.canvasjs.com/canvasjs.min.js"></script>
</head>
<body>
<div id="chartContainer" style="height: 300px; width:100%;">
</div>
</body>
</html>
I got one code from canvasjs blog in that graph reads data from csv file and code is shown below.
`<!DOCTYPE html>
<html>
<head>
<script type=”text/javascript” src=”http://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.1/jquery.js”></script>
<script type=”text/javascript”>
$(document).ready(function () {
$.ajax({
type: “GET”,
url: “data.csv”,
dataType: “text”,
success: function (data) { processData(data); }
});
function processData(allText) {
var allLinesArray = allText.split(‘\n’);
if (allLinesArray.length > 0) {
var dataPoints = [];
for (var i = 0; i <= allLinesArray.length – 1; i++) {
var rowData = allLinesArray[i].split(‘,’);
if(rowData && rowData.length > 1)
dataPoints.push({ label: rowData[0], y: parseInt(rowData[1]) });
}
chart.options.data[0].dataPoints = dataPoints;
chart.render();
}
}
var chart = new CanvasJS.Chart(“chartContainer”, {
theme: “theme1”,
title: {
text: “Welcome to World of IOT”
},
data: [
{
type: “line”,
dataPoints: []
}
]
});
});
</script>
<script type=”text/javascript” src=”canvasjs.min.js”></script>
</head>
<body>
<div id=”chartContainer” style=”height: 500px; width: 80%;”></div>
</body>
</html>
How can i modify above two code and achieve reading data from csv and do dynamic plotting.?
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This topic was modified 9 years, 1 month ago by saurabh. Reason: to show effect of code
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This topic was modified 9 years, 1 month ago by saurabh.