Montgomery County

MD Counties Map_Step 1

This choropleth map displays population density for census tracts in Montgomery County, Maryland, using a threshold color scale from light to dark red. It renders SVG paths via `d3.geoPath` with a conic conformal projection, merging TopoJSON tract boundaries from a local dataset. The code loads tract geometries and population data with `d3.queue`, calculates density by dividing population by land area, and applies `d3.scaleThreshold` with `d3.schemeOrRd`. A legend built with `d3.axisBottom` and a power scale explains the color ranges.

91% match

MD Counties Map

This choropleth map displays the population density of Maryland census tracts using a sequential color scale. The visualization loads GeoJSON and population data from external URLs, then uses the `topojson` library to convert the data before rendering it as SVG paths projected with `d3.geoConicConformal` and `d3.geoPath`. A draggable circle allows hovering to query tract attributes, and a legend with thresholds is generated using `d3.scaleThreshold`, `d3.scalePow`, and `d3.axisBottom`.

86% match

MD Counties

A choropleth map of Maryland counties colors each county by population density using a threshold scale and the d3.schemeOrRd color scheme, with county boundaries derived from a TopoJSON file. Hovering over a county highlights it with a thicker stroke, displays its name, population, land area, and density in an info box, and renders a small pie chart using d3.pie and d3.arc showing the county's population, land area, and density. The map uses a d3.geoConicConformal projection, along with topojson-client to parse geographic data and d3-scale-chromatic for colors.

86% match

county names May 5

This example displays a choropleth map of Maryland census tracts colored by population density using a threshold scale with the d3.schemeOrRd color scheme. It uses d3.geoConicConformal projection, d3.geoPath, and topojson to render tract and county boundaries. A yellow draggable circle initially positioned at Rockville, MD, uses d3.drag to update its position and reveal the containing county name in a tooltip via d3.geoContains and projection.invert. The population data is loaded from external JSON files.

86% match

May 5

This visualization displays population density across Maryland census tracts using a choropleth map, with color thresholds from d3.scaleThreshold and d3.schemeOrRd. It renders SVG paths via d3.geoPath with a geoConicConformal projection, loading TopoJSON census tract boundaries and a population dataset through d3.queue. County outlines are drawn from merged geometries. A draggable yellow circle marks Rockville, repositioning via d3.drag, while hovering shows the county name in a tooltip using d3.geoContains to test point-in-polygon.

May 4 in class

This choropleth map of Maryland census tracts displays population density using a threshold scale with the sequential color scheme d3.schemeOrRd, with county boundaries outlined in red. It includes a draggable yellow circle representing Rockville, MD, whose movement is handled by d3.drag, and an HTML tooltip div is appended to the body. The map is rendered as SVG using d3.geoPath with a conic conformal projection, while population data comes from a separate JSON file joined to TopoJSON tracts. A color legend is built with d3.axisBottom and a power scale.

MD Counties with US Atlas

This choropleth map of Maryland counties visualizes population density using a conic conformal projection fitted to GeoJSON county boundaries. The code loads topojson and population data, calculates density as population divided by land area, and fills each county with colors from the d3.schemeOrRd sequential color scheme via d3.scaleThreshold. Hover interactions highlight counties in red. A legend built with d3.axisBottom and d3.scalePow shows the density thresholds. The visualization uses d3.v4, topojson.v2, and renders SVG paths with d3.geoPath, sourced from UMBC VIS class data.

md-geometry

This visualization shows population density across Maryland census tracts using a choropleth map. The color scale maps density values to an orange-red sequential palette, with darker shades indicating higher population per square mile. Built with D3 v4, it loads TopoJSON tract boundaries and CSV population data, joins them by county and tract FIPS codes, and calculates density by dividing population by land area in square miles. The `d3.geoConicConformal` projection fits the state geometry using `projection.fitSize`, and `d3.geoPath` renders the SVG paths with `d3.scaleThreshold` for coloring.