Peakdet is a NodeJS library for detecting peaks and valleys in data. Peakdet takes a JavaScript implementation of a MATLAB script for detecting peaks and packages it as a Node library and adds a test.

Usage

The library is in the peakdet.js file and an example of its use is:

var peakdet = require('./peakdet.js');

// Create the vector that we want to detect peaks in
v = []
for (var i = 0; i < 10; i += 0.001) {
  v.push(0.3 * Math.sin(i) + Math.sin(1.3 * i) + 0.9 * Math.sin(4.2 * i))
}

// Call the peakdet function, the second argument is the minimum differece
// between the peak and its surrounding points
res = peakdet.peakdet(v, 0.5)

peaks = res.peaks
valleys = res.valleys

for (var i=0; i < peaks.length; i++) {
  console.log("Peak " + peak[i])
}

for (var i=0; i < peaks.length; i++) {
  console.log("Valley " + valley[i])
}

Tests

To run the suite of tests:

1. Install NodeJS.
2. Run nodejs test.js
3. If everything's working it should say something like Passed tests.

The test.ods file is a spreadsheet containing the test data.