How to use
A stacked dot plot shows the distribution of a small numerical sample without grouping observations into histogram bins. It helps students and teachers inspect repetitions, gaps and clusters, and lets you compare the visual stack heights with an exact frequency table. Enter each observation once; repeated observations must appear repeatedly in the input.
- Replace the example values with your own data. Use a decimal point, even when your language normally uses a decimal comma.
- Choose Calculate or press Enter. Read the result together with the plot and the detailed table.
- Copy result copies the confirmed numbers as plain text. Editing an input clears the previous result and copy state, while the graph previews valid current inputs. Clear empties inputs, results and graph without restoring the example.
How it works
The calculator sorts numerical values and counts exact duplicates. A value that occurs four times produces four vertically stacked circles at that horizontal coordinate. It does not round nearby values into a shared category. The total number of circles equals the number of accepted observations, and the total of the frequency table is the same sample size.
The horizontal axis is numerical: a gap of two units is twice as wide as a gap of one unit. The vertical direction records frequency rather than a second measured variable. The chart expands horizontally where practical and allows scrolling. Very close values can still overlap on a finite display, so always use the table to distinguish them. No observations are removed to make the chart fit.
Examples
Enter 1, 2, 2, 3, 3, 3, 5. The result contains seven observations and four distinct values. Frequencies are 1 → 1, 2 → 2, 3 → 3 and 5 → 1. The gap from 3 to 5 is twice the gap from 2 to 3.
Enter −1, −1, 0.25, 0.2501, 2. There are five observations and four distinct values. Only −1 stacks twice. The two positive decimals remain separate rows even if their circles are too close to distinguish at the current scale.
Uses and limits
The limit is 200 observations, including repetitions. Separate numbers with spaces, commas or semicolons, use a decimal point and omit thousands separators. Input must be numeric, with at most 15 significant digits. Zero is valid; nonzero magnitudes range from 10⁻⁹ through 10⁹. An over-limit or malformed list produces an error with no partial chart.
Use the scrollable plot for tall stacks and wide numerical ranges. The full table is often easier to read on a phone or when one extreme value compresses the other observations. This is a single-sample numerical dot plot, not a scatter plot, category chart or inference test. A visible cluster does not establish a cause, trend or representative sample.
Frequently asked questions
Are nearby decimal values combined?
No. For example, 0.25 and 0.2501 have separate frequencies. They are shown at proportional horizontal positions rather than being spaced evenly as categories.
Why is a single stack so tall?
All observations may share one value. The plot still draws one circle for every observation, and its own region scrolls vertically when necessary.
Can I enter a value followed by its frequency?
No. The input is a list of individual observations. Entering 2, 5 means one observation at 2 and another at 5, not five copies of 2.
What does Copy result include?
The sample summary and complete frequency table as text after Calculate. There is no image export or persistent storage. Editing removes the old confirmed result and copy state, while valid current data immediately update the preview.