the dotplot

One dot per thing, stacked up wherever it lands. You can still count every dot, and the piles show where they gather.

What it leaves outAbove a few hundred values the dots run out of room and start to overlap, so the stack stops being an honest count.

2 · intermediate · cartesian · level 2 · ask who counted · taught in dive 2.4 · dive 3.1

GAISE II · Level A p.23, Level B p.45

Three worked examples

How many days were like today?

Before you lookWrite down roughly how many service requests you think a normal day brings.

civichist_la_311_per_day.csv · 365 rows · 2 columns

how many service requests came in on each of 365 days

What to look atOne dot per day, stacked where they land. You can count the dots in a stack — that is what a histogram takes away from you.

This example draws itself with a small script. With scripting off you can still read every word on this page, and the file itself is at data/hist_la_311_per_day.csv.

earth and spacenoise_socal_m4_by_year.csv · 30 rows · 2 columns

how many magnitude-4-or-greater quakes happened each year for thirty years

What to look atThirty dots. Small enough to count, which is exactly when a dotplot beats everything else.

This example draws itself with a small script. With scripting off you can still read every word on this page, and the file itself is at data/noise_socal_m4_by_year.csv.

teen healthteen_experience_spread.csv · 290 rows · 4 columns

ten things about teenagers, every group, one dot each

What to look atTwo hundred and ninety dots, and every one is a real group you can hover. The box plot of this same file draws ten boxes over these dots — look at 'plays a sport' here and there, and name one thing the box hid. The flat column on the right is screens: nearly every group does that alike.

This example draws itself with a small script. With scripting off you can still read every word on this page, and the file itself is at data/teen_experience_spread.csv.

the pool

Now build one yourself.

The pool opens with this file and this shape already drawn, so your first move is to change something rather than to start from nothing. Bring your own CSV if you have one. Nothing is uploaded anywhere — the chart is drawn in your browser, your work saves there, and it downloads as a picture or as a project file you can open again.

Open the pool → the dotplot · hist_la_311_per_day.csv