Difference: DuckyInfoVisMilestones (1 vs. 2)

• How do I deal with the huge dynamic range?
  • Offer several:
    • Which?
    • How does user switch between them?
• Do I allow people to change range on the fly?

• Write code to create PNG from one known polygon extracted from shapefile; overlay on Google Maps
• Write code to create PNG from several known polygons extracted from shapefile; overlay on Google Maps
• Write code to create PNG from several known polygons, shaded with data from population file; overlay on Google Maps

• Given zoom level and map lat/long boundaries, figure out how to tell which polygons are visible

• Write code to create PNG from lat/long boundaries at one zoom level

• Port code to Dreamhost
• Plug code into CGI
• Figure out how to redraw with panning
• Write code to deal with panning via controls
• Figure out how to drag the overlay (ulp, what if not possible?)

• 13 November: One PNG file generated with one polygon extracted from dataset, requiring:
  • extracting polygons with the Shapefile C library
  • extracting the appropriate demographic data from the dataset with the Shapefile C library and the data files
  • associating polygon <->demographic data
  • understanding the gd library well enough to generate a PNG with a transparent polygon

• • determining which polygons will be visible given lat/long bounds
  • iterating through visible polygons, drawing each

Ducky's Info Vis Milestones

Current worries

• How do I capture clicks through the overlay (the map/satellite lens uh-oh does things differently).
• Speed speed speed
• LD_LIBRARY_PATH / static libraries nonsense

Ducky's Info Vis Tasks

• Explore different color bars
• Thoroughly understand and document how census bureau data fits together

• Develop a simple test suite for PNG manipulation
• Write code to create PNG from one known polygon extracted from shapefile; overlay on Google Maps
• Write code to create PNG from several known polygons extracted from shapefile; overlay on Google Maps
• Write code to create PNG from several known polygons, shaded with data from population file; overlay on Google Maps

• Given zoom level and map lat/long boundaries, figure out how to tell which polygons are visible first pass done
  • test better
• Write code to retrieve a polygon based on lat/long.
• Write code to create PNG from lat/long boundaries at default zoom level
• Figure out how to aggregate data from multiple polygons
• Write code to aggregate data
• Modify code to create PNG from lat/long/zoom data
• Overlay images dynamically on Google Maps

• (aggressive) Add sliders to allow changing the parameters of the image (e.g transparency, hue)
• (aggressive) Add radio buttons to change data sets
• (aggressive) Allow user to choose from several different years of data
• (extremely aggressive) allow semi arbitrary data to be mapped
  • design with XML format
  • design interactive
  • find information about Mike Beckerle's data description language

Proofs of concept:

• simple walking duck
• two overlays
• overlay transparent Google Maps over Google satellite images

Promised milestones

• 4 November: Proposal finished
• 13 November: One PNG file generated with one polygon extracted from dataset, requiring:
  • extracting polygons with the Shapefile C library
  • extracting the appropriate demographic data from the dataset with the Shapefile C library and the data files
  • associating polygon <->demographic data
  • understanding the gd library well enough to generate a PNG with a transparent polygon
• 20 November: Functional panning, perhaps limited to one US state and perhaps slow, requiring:
  • determining which polygons will be visible given lat/long bounds
  • iterating through visible polygons, drawing each
  • plugging overlays into the Google Maps API
• 4 December: Functional zooming
  • determining which polygons will be visible given lat/long bounds and zoom level
  • aggregating lower-level data (note that I do not think this is trivial)
  • killing small code gremlins
• 11 December: Performance tuning and bug fixes done, probably requiring finishing:
  • pre-processing census bureau data into a form that is easier to extract quickly
  • prefetching of neighboring overlays
  • caching previously-used overlays
  • killing large code gremlins
• 16 December: Status update due, requiring
  • bibliography done
  • writing done
• 19 December: Final due date, requiring
  • learning LaTeX
  • coercing text into journal format
  • killing LaTeX gremlins

• Set ALLOWTOPICCHANGE = DuckySherwood