Make a Minnesota precinct map with 2014 turnout data

make_mn_precincts.sh

wget ftp://ftp.gisdata.mn.gov/pub/gdrs/data/pub/us_mn_state_sos/bdry_votingdistricts/shp_bdry_votingdistricts.zip && \
  unzip shp_bdry_votingdistricts.zip  && \
  shp2json bdry_votingdistricts.shp | \
  ndjson-join --left 'd.properties.COUNTYCODE + d.properties.PCTCODE' 'd.county_id + d.precinct_num' <(ndjson-split 'd.features') <(csv2json -n precincts_2014.txt -r ";") | \
  ndjson-map 'Object.assign(d[0].properties, d[1]), d[0]' | \
  ndjson-reduce 'p.features.push(d), p' '{type: "FeatureCollection", features: []}' | \
  geoproject 'd3.geoIdentity().reflectY(true).fitSize([960, 960], d)' | \
  geo2topo precincts=- | \
  toposimplify -f -p 0.05 | \
  topoquantize 1e5 > ./mn-precincts-albers-d3.json && \
  rm bdry_votingdistricts.* &&
  rm -rf ./metadata &&
  rm shp_bdry_votingdistricts.zip