Session 3: Summary statistics, groups & rollups – Intro to data wrangling & analysis in JavaScript
Session 3 topics:
Descriptive statistics with d3 methods
Rollups (summary statistics by group)
Map and get
In this course, you’ll learn basic skills and methods for working with data in JavaScript, including: arrays and how to work with them, essential programming methods and operators (like arrow functions, iteration, and logical operators), basic data wrangling, and exploratory analyses with descriptive statistics and data visualization.
Instructor: Allison Horst (Data Scientist Advocate at Observable)
00:00 - Welcome and warm-up activity
14:43 - Descriptive statistics with D3 methods (d3.min, d3.extent, d3.mean, d3.deviation, d3.count)
29:35 - d3.group, Map, and get
43:38 - d3.rollup for summary statistics by group
57:40 - Observable Plot with a reduced (mean) value
Aggregated course materials: https://observablehq.com/collection/@...
Session 3 notebook: https://observablehq.com/@observableh...