Maps and Animations
stat/engl 332
Outline
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Choropleth maps
Cartogram approaches
Animations
Maps are old tools …
… and almost omnipresent
Maps
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allow us to see information ‘in place’
geographical pattern (boundary tracking)
… how could we get insight to patterns?
Choropleth Maps
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Choropleth (greek,
area of multitude) or
thematic map:
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areas are shaded/
colored according to
another covariate
Walker,,Francis,A.,,comp.,,Sta1s1cal*
Atlas*of*the*United*States*Based*on*the*
Results*of*the*Ninth*Census*1870.,,U.S.,
Census,Office.,,New,York:,,Julius,Bien,,
1874.,,,Plate,25.,
,
hOp://memory.loc.gov/ammem/
gmdhtml/census.html,,
http://www.weather.gov
NOAA
Who won the 2012
election?
where are we now?
diffusion based cartogram
Cartograms
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Choropleth maps show traditional geography: distort
data e.g. population in DC is larger than in South
Dakota, but DC is not visible
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Cartograms distort geography in different ways:
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diffusion based adjusts area to show quantity,
neighboring areas touch (contiguous), shapes
distorted
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other approaches …
Iowa by county population, Wallace, 1926
overall shape is familiar
individual shapes distorted
neighbors rearranged
Scaling idea
http://style.org/iowacaucus/
Dorling’s cartogram
http://www.datadrivenconsulting.com/js/protovis/
cartogramemp.html
J.,R.,Dodge.,,Album*of*Agricultural*Graphics.**Washington,,D.,C.:,,U.S.,Department,of,
J. R. Dodge. Album of Agricultural Graphics. Agriculture,,1890.,,Courtesy,Iowa,State,University,Library,,Department,of,Special,Collec1ons.,
Washington, D. C.: U.S. Department of Agriculture, 1891.
Maps & symbols
http://www.fec.gov/disclosurep/pnational.do?cf=phome
Earthquakes of the last 30 days
Isopleth Maps (Contour Maps)
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Maps overlaid with lines of continuous
covariate, along the lines the covariate
doesn’t change
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e.g. maps of barometric pressure, elevation
maps, …
Geography + Time = Animation?