Code

D3.js

Select & Style

Select elements and apply styles with d3.select() and d3.selectAll().

Data Binding

Bind arrays to DOM elements using the enter / join / exit pattern.

Bar Chart

Vertical bar chart with scaleBand, scaleLinear, and axis helpers.

Scales

Linear, sqrt, log, and sequential colour scales compared visually.

Line Chart

Multi-series time-series line chart with area fill.

Scatter Plot

Scatter plot with colour and size encoding per group.

Pie / Donut Chart

Donut chart using d3.pie() and d3.arc() with percent labels.

Area Chart

Stacked area chart with d3.stack() and scaleTime.

Histogram

Frequency histogram with d3.bin() and a normal-curve overlay.

Transitions

Animated attribute changes with easing functions and callbacks.

Zoom & Pan

Scroll-to-zoom and drag-to-pan via d3.zoom().

Force Graph

Draggable force-directed network graph with forceSimulation.

Treemap

Hierarchical squarified treemap with d3.hierarchy() and d3.treemap().

Chord Diagram

Relationship matrix visualised as a chord diagram with d3.chord().

Brush

Focus+context: brush a time window in the overview to filter the detail view.

Generative Art

Animated flow-field generative art with sine-harmonic noise and sequential colour scales.

Line Chart

Intermediate Multi-series line chart using scaleTime, d3.line() path generator, area fill, and curveCatmullRom smoothing. d3-shape/line

const x = d3.scaleTime()
  .domain(d3.extent(data, d => d.date))
  .range([0, innerWidth]);

const y = d3.scaleLinear()
  .domain([0, 90])
  .range([innerHeight, 0]);

// Line generator
const line = d3.line()
  .x(d => x(d.date))
  .y(d => y(d.value))
  .curve(d3.curveCatmullRom);

// Area fill under the line
const area = d3.area()
  .x(d => x(d.date))
  .y0(innerHeight)
  .y1(d => y(d.value))
  .curve(d3.curveCatmullRom);

g.append('path').datum(data)
  .attr('fill', '#4f46e520')
  .attr('d', area);

g.append('path').datum(data)
  .attr('fill', 'none')
  .attr('stroke', '#4f46e5')
  .attr('stroke-width', 2.5)
  .attr('d', line);

Key APIs

d3.scaleTime() — maps Date objects to pixel positions
d3.line() — path generator for line charts
d3.area() — path generator with y0 baseline for area fill
d3.curveCatmullRom — smooth curve interpolation
d3.extent(array, accessor) — [min, max] helper
d3.timeParse(format) / d3.timeFormat(format) — date parsing & formatting