Class #13 demo

Class 4

This example displays a map of the United States using D3 v4 and topojson, with a second layer of earthquake points from the USGS live feed. The map is rendered as SVG paths via the `d3.geoPath` and `d3.geoAlbersUsa` projections, while quake locations are drawn as crimson paths. A mouseover function uses `projection.invert` and `d3.mouse` to display the geographic coordinates of the cursor. Two separate `<g>` elements separate the state and earthquake layers.

Class 5

This visualization displays earthquake locations across the United States from the USGS live feed, with each quake colored by magnitude using a d3.scaleOrdinal color scale. State boundaries render as gray paths via TopoJSON and d3.geoPath with an AlbersUSA projection. A legend with circles shows magnitude ranges and counts, while hovering reveals coordinates through d3.mouse and projection.invert. The map filters quakes to viewport-visible coordinates and removes legend entries exceeding the largest observed magnitude.

class 3 - states

This example displays a map of the United States with earthquake locations overlaid as crimson points. The map is rendered using SVG paths created with `d3.geoPath` and a `d3.geoAlbersUsa` projection, while earthquake data is loaded from the USGS GeoJSON feed and plotted with the same path generator. The visualization also shows the latitude and longitude of the mouse cursor in a separate text element, using the projection’s `invert` method to translate screen coordinates to geographic coordinates.

Class 5

This visualization displays earthquakes from the past week across a map of the United States, with points colored by magnitude and a legend showing the number of quakes in each magnitude range. It uses d3.geoPath with a d3.geoAlbersUsa projection to render TopoJSON state boundaries, while earthquake data arrives as GeoJSON from the USGS feed. The map includes a draggable orange circle, and mouse movement updates a readout of geographic coordinates using the inverse projection.

class 4 - states

This example displays a map of the contiguous United States with earthquake locations overlaid as crimson points. The map is rendered using `d3.geoPath` with the `d3.geoAlbersUsa()` projection, while earthquake data is pulled from the USGS live GeoJSON feed. State boundaries come from a local US GeoJSON file processed with `topojson.feature`. The visualization also includes a static legend and interactive coordinate display, which updates as the mouse moves across the map. All drawing is performed with SVG elements.

Class 5

This map of the United States displays earthquake locations from the USGS live feed for the past week, with each quake represented as a circle colored by magnitude using a D3 ordinal color scale. The visualization uses `d3.geoAlbersUsa` for the map projection, `d3.geoPath` to render state boundaries, and `topojson.v2` for GeoJSON conversion. A legend at the right shows magnitude ranges with quake counts, while mouseover coordinates are displayed via a D3 text element.

class-02 demo

This example plots earthquake data from the USGS feed as filled paths on a map of Oklahoma, using county and state boundary shapes from a TopoJSON file. The visualization uses an Albers USA projection via `d3.geoPath` to render both the geographic outlines and the quake features, with a threshold magnitude of 2.5 filtering the displayed events. Earthquakes appear as crimson semi-transparent shapes, while the map layer is drawn separately in a background group. The code also logs earthquake counts for California and the earliest event time to the console.