lowpassf is simple lowpass filter libary for javascipt/node.js. It can be used to smooth real-time data including high frequency noises.
This library provides 2 ways.
- Simple moving average
- Weighted moving average
It is licensed under MIT license.
var filter = new LowpassFilter();
//Set average logic from ( filter.LinearWeightAverage/filter.SimpleAverage)
filter.setLogic(filter.LinearWeightAverage);
var data = [100, 100, 200, 200, 300, 300]
var i;
for (i = 0; i < data.length; i++) {
//put current value
filter.putValue(data[i]);
//Get the latest calculated moving average of the values putted so far
var filteredValue=filter.getFilteredValue();
console.log(filteredValue);
}Here is a simple example. https://riversun.github.io/lowpassf/
You can import library with npm.
Install
npm install --save-dev lowpassf
app.js
var LowpassFilter = require('lowpassf');
var filter = new LowpassFilter();
//Set average logic from ( filter.LinearWeightAverage/filter.SimpleAverage)
filter.setLogic(filter.LinearWeightAverage);
var data = [100, 100, 200, 200, 300, 300]
var i;
var sampleRange = 20;
console.log("Prepare data...");
for (i = 0; i < data.length; i++) {
console.log("data[" + i + "]=" + data[i]);
}
console.log("");
console.log("Start filtering...");
//Specify how many items to buffer
filter.setSamplingRange(sampleRange);
for (i = 0; i < data.length; i++) {
//put current value
filter.putValue(data[i]);
//get current "filtered" value
//Get the latest calculated moving average of the values putted so far
var filteredValue = filter.getFilteredValue();
var logStr = "data[" + i + "]=" + data[i]
+ " added. current filtered val is "
+ filteredValue;
console.log(logStr);
}run on node.js
node app.jsPrepare data...
data[0]=100
data[1]=100
data[2]=200
data[3]=200
data[4]=300
data[5]=300
Start filtering...
data[0]=100 added. current filtered val is 100
data[1]=100 added. current filtered val is 100
data[2]=200 added. current filtered val is 150
data[3]=200 added. current filtered val is 170
data[4]=300 added. current filtered val is 213.33333333333334
data[5]=300 added. current filtered val is 238.0952380952381
<!DOCTYPE html>
<html lang="en">
<body>
<script src="src/LowpassFilter.js"></script>
<script>
console.log = function (s) {
document.write(s + "<br>");
}
var filter = new LowpassFilter();
//Set average logic from ( filter.LinearWeightAverage/filter.SimpleAverage)
filter.setLogic(filter.LinearWeightAverage);
var data = [100, 100, 200, 200, 300, 300]
var i;
var sampleRange = 20;
for (i = 0; i < data.length; i++) {
console.log("data[" + i + "]=" + data[i]);
}
//Specify how many items to buffer
filter.setSamplingRange(sampleRange);
for (i = 0; i < data.length; i++) {
//put current value
filter.putValue(data[i]);
//Get the latest calculated moving average of the values putted so far
var filteredValue=filter.getFilteredValue();
var logStr = "data[" + i + "]=" + data[i] + " added. current filtered val is " +filteredValue;
console.log(logStr);
}
</script>
</body>
</html>