Quick start
- Paste grouped classes or raw scores, then adjust width/start.
- Unequal widths? The histogram switches to frequency density so bar area still equals frequency.
- Copy a shareable URL or export CSV/SVG for handouts.
All parsing and plotting stay in your browser. No uploads.
Inputs & settings
3-step guide: enter → auto-update → share/export
| Lower bound L | Upper bound U | Frequency f |
|---|
Classes are treated as [L, U).
Tip: Bar height uses frequency density when widths differ so area still equals frequency.
Results
Total N: 0
Histogram y-axis: Auto
Graphs
Histogram
Bar height
Cumulative frequency (ogive)
Upper bound vs cumulative frequency
Summary
Bar area tracks frequency, and ogive points sit on each upper boundary.
Steps & reasoning
Share & export
FAQ
Should histogram height use frequency or frequency density?
If all widths match, frequency works because bar area tracks count. When widths differ, use frequency density so each bar area equals its frequency.
Where do ogive points go?
At each upper boundary with the cumulative frequency there, matching classes defined as [L, U).
What do relative and cumulative relative frequency mean?
Relative frequency is f/N; cumulative relative is the running total. The final value is always 1 (100%).
Why highlight modal or median classes?
They show where the distribution peaks and where half the observations accumulate. With unequal widths, the modal class uses the highest frequency density.
Is any data uploaded?
No. Everything runs locally, and the share URL only stores parameters in the query string.