What this site does. You bring a table of numbers, it gives you
numbers back. This page finds the peaks in your data - which bumps are real, where
each one is, how tall and how wide - and fits overlapping Gaussian peaks to split
them apart. It runs entirely in your browser — nothing is uploaded, nothing is
stored. If you want the reasoning rather than the answer, the
peak finding article explains every number
on a worked example.
Noise makes a small local maximum every few samples; the prominence filter decides
which bumps count. Two peaks closer than their width merge into one bump: raise the
number of peaks and fit. Lorentzian and Voigt shapes, the derivative and wavelet
finders and a per-peak editor are on the
advanced calculator.
- Paste your data into the Input grid — straight from a
spreadsheet, or as CSV/TSV text — or import a CSV/TSV file.
Column x, then y1 and y2. Up to 5,000 rows. Rows are sorted by x; one y per x.
- Peaks are found at once. As soon as the input is applied, every
local maximum that passes the filters is marked on the chart, and the Output grid
lists its position, height and half-prominence width (HPW): the width at half its
prominence, read straight off the data. FWHM and area wait for the fit.
- Filters. Prominence is how far a peak stands
above its surroundings, as a fraction of the column's range (0.1 = 10 %).
Min height drops peaks below a level; leave it blank for off.
Distance drops a peak that sits closer than that many samples to a taller one.
The ▲▼ buttons and the mouse wheel on prominence and distance find again at once.
- Peaks sets how many Gaussians the fit uses. It starts at the
number found; raise it when a bump hides a second peak in its shoulder. A change
to the grid or a filter resets it.
- Press fit. The chart shows the input as a light black line,
each fitted Gaussian as a green dashed line and their sum as a red line. The Output
grid then lists each peak's fitted position, amplitude (its height above the baseline), FWHM and
area. Each fitted amplitude is held at 0 or above: a peak stands up from the
baseline, so the fit never answers with a negative peak. A change to the grid, a filter or the peaks count clears the fit.
- Show picks which y the chart draws; each y keeps its own peaks
count. Under the chart: R² and the residual RMS of the shown y.
Export saves the Output grid as a CSV/TSV file.