Non-Contiguous Cartogram

100%

Non-Contiguous Cartogram

✓ Published0🌍 Public

Last edited Feb 13, 2020

Created on Nov 11, 2012

This example displays a non-contiguous cartogram of U.S. obesity rates, where each state is rescaled around its centroid so that its area encodes the data value while preserving local shape. The distortion is achieved by applying a `transform` attribute to each state path, using `d3.geo.path` to compute centroids and `Math.sqrt` to determine scale. State boundaries come from the U.S. Census Bureau. The code uses `d3.json` to load TopoJSON and `d3.select` to build the SVG scene.

AI-generated description

Unlike choropleth maps, cartograms encode data using area rather than color, resulting in distorted geographic boundaries. In this example, states are rescaled around their centroid, preserving local shape but not topology. Inspired by Zachary Johnson. Non-continguous cartogram design invented by Judy Olsen. U.S. state and county boundaries from the U.S. Census Bureau, simplified using GDAL and MapShaper.

gpl-3.0 Licensed

Similar vizzes

Loading thumbnail…

Dorling Cartogram

A pseudo-cartogram maps obesity rates across U.S. states, using circles sized by value and positioned near their geographic origins. The visualization employs D3.js (v3) with an Albers USA projection and a `d3.layout.force` simulation to resolve overlaps while preserving locality. Circle radii are scaled via `d3.scale.sqrt` from CDC 2008 data, rendered as SVG shapes.

Mmbostock

82% match

Loading thumbnail…

Demers Cartogram

This visualization shows obesity rates across U.S. states as a pseudo-cartogram, encoding each state’s value as a square whose area is proportional to the obesity ratio. Rather than preserving adjacency between states, the layout uses a force simulation with `d3.forceSimulation`, applying `d3.forceX` and `d3.forceY` to pull each square toward its original Albers USA projection centroid while a custom collide force prevents overlap. The obesity data is drawn from CDC 2008 estimates and rendered as SVG rectangles, colored uniformly gray.

Mmbostock

82% match

Loading thumbnail…

D3 DataBinding

The example maps U.S. adult obesity rates from CDC 2008 data by projecting state boundaries and scaling each state’s area according to its value. It uses D3 v5 with `d3.geo.path()` to render TopoJSON features, applying a centroid-based transform that proportionally enlarges states with higher obesity ratios while adjusting stroke width inversely. The visualization appears twice on the page, with the second instance likely reusing the same logic. Data is embedded as an array of per-state values, and the map relies on TopoJSON’s `topojson.feature` to extract geometries.

663anp3ca

81% match

Loading thumbnail…

Demers Cartogram

This interactive SVG cartogram visualizes U.S. adult obesity rates from CDC 2008 data, representing each state as a square whose size scales with the prevalence of BMI ≥ 30. The map preserves approximate geographic locality—squares stay near their original positions—rather than maintaining adjacency between states. A custom collision force iteratively pushes overlapping rectangles apart while d3.forceSimulation with d3.forceX and d3.forceY pulls each square toward its projected Albers USA centroid. The code uses a manual collide function with four iterations per tick to separate the rect elements.

深深度碎片

79% match

Loading thumbnail…

U.S. States TopoJSON

This example shows a map of the United States rendered as SVG paths, where individual states turn red when hovered. The map uses the TopoJSON `us-atlas` file, loaded via `d3.json`, and the code relies on the `topojson` library to convert the TopoJSON topology into geographic features. The rendering is done with `d3.geoPath` to project the geometry, and state borders are drawn as a separate path using a mesh that highlights each boundary. No interaction beyond the hover effect is implemented.

Mmbostock

74% match

Loading thumbnail…

U.S. State Mesh

This example visualizes the starting point of every arc in a TopoJSON file of U.S. state boundaries, rendered as a black dot on a mesh of state outlines. It loads the topology from `us.json` and uses `d3.geo.path()` with a `null` projection to draw the mesh. The code then plots each arc's start coordinate as a small circle, applying a custom `transform` function to map the TopoJSON coordinates using the file's `transform.scale` and `transform.translate` values. The visualization highlights how polygon boundaries are decomposed into shared arcs, revealing the topology's underlying structure.

Mmbostock

74% match

Loading thumbnail…

Zoomable Geography

This example shows U.S. states and counties rendered as SVG paths, which can be panned and zoomed with the mouse. It uses d3.behavior.zoom to modify the transform of a group element, letting the browser redraw geographic features quickly without reprojection. The code loads TopoJSON data and renders it with d3.geo.path, using a null projection to preserve the pre-computed geometry. Border stroke widths are adjusted inversely to the zoom scale to maintain a constant visual weight.

Mmbostock

73% match

Loading thumbnail…

Symbol Map

A symbol map displays the population of each U.S. state as a circle centered on the state’s centroid, with circle area proportional to population via a square-root scale. The visualization overlays these circles on a gray state map rendered with `d3.geo.path`, using TopoJSON for state boundaries and GeoJSON for state centroids. The code loads both datasets with the queue library, sorts states by population, and draws each symbol as an SVG path with a white stroke and semi-transparent steelblue fill.

Mmbostock

73% match