What this site does. You bring a table of numbers, it gives you
numbers back. This page takes the slope of your data at every point (the
derivative) or the running area under it (the cumulative integral), and the
area over any x range you set. It runs entirely in your browser — nothing is
uploaded, nothing is stored. If you want the reasoning rather than the answer, the
derivative and integral article walks
through each method and where each one fails.
A derivative of noisy data is mostly noise: smooth the data first, or use the
Savitzky-Golay derivative 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 up to three y columns. Up to 5,000 rows.
- x may be unevenly spaced and in any order: rows are sorted by x. A row with
no number in x is skipped; a blank y cell is skipped for that column only.
Every x must be different.
- Pick the Operation — its Method follows. Derivative uses the central difference,
one-sided at the first and last row. Integral uses the trapezoid rule and
starts at 0 at the first x.
- Press calculate. The upper chart shows your data, the lower
chart the result. The Output grid lists x, then the result for each y column.
Export saves it as a CSV/TSV file.
- Area over a range (integral only) — under the charts, set
From and To and pick Signed (area below the axis subtracts) or Absolute (every
part adds). The area of each y column shows beside them.
- Real time range — move the range live on the From and To boxes.
- ▲▼ buttons or the mouse wheel over the
box: the end moves by 0.1 and the area is recomputed at once.
- Digit wheel: over the box, the wheel steps the digit just
left of the mouse pointer.
- Limits: both ends must lie inside the data's x, From below
To; anything else is refused with a reason, never moved for you.
- Typing or the arrow keys change the box only; press
calculate to recompute.