The Presidential-race polling data on www.electoral-vote.com are great, and the site’s plots do help visualize the country-wide race. But I want to see all the historical data for all of the states at a glance. To this end, I have taken the data from the site (as of the morning of November 2, 2004) and created this all-inclusive summary plot that shows the state-by-state polling results from September 1, 2004 through November 2, 2004:
Some things to observe:
- Battleground states are polled frequently; others, hardly at all
- Wisconsin’s polling data suggest that Bush once had the state but lost it
See anything else interesting?
If you want to see the code I used to generate the plot, read on.
The code
In case you’re curious, here’s the shell script and R code that I used to generate the above plot:
#!/bin/bash
# Generate all-states polling chart from electoral-vote.com data
# Tom Moertel <tom@moertel.com>
# 2004-11-02
# config
CSV=allpolls.csv
FILEBASE=polls-by-state
GS="gs -dSAFTER -dBATCH -dNOPAUSE"
# set up filenames
EPS=$FILEBASE.eps
PNG=$FILEBASE.png
PDF=$FILEBASE.pdf
# get polling data and add header to it
echo "Making sure we have polling data (delete $CSV to force download) ..."
[ -f $CSV ] ||
( echo -n date,series,state,ev,kerry,bush,nader,released,
echo unk2,unk3,unk4,unk5,unk6,unk7,unk8,source
GET http://www.electoral-vote.com/info/$CSV
) > $CSV
# use R to generate plot in Postscript format
# (uses X11 window so we can see the plot in passing)
echo Generating plots ...
R --no-save --no-init-file --no-restore-data <<EOF
polls <- read.csv("$CSV")
require("lattice")
trellis.device(x11, theme=col.whitebg())
p <- xyplot(kerry + bush ~ date | state, data=polls,
main="Polling Numbers by State (Nov 2)",
auto.key=list(rectangles=F,x=.75,y=.875,corner=c(1,1)),
xlab="Elapsed days (1 = Sep 1)",
ylab="Percentage who would vote for candidate")
p
dev.copy2eps(file="$EPS",family="Helvetica-Narrow")
EOF
# create other graphics formats
echo Rasterizing into PNG format ...
$GS -sDEVICE=pngalpha -dBackgroundColor='16#ffeebb' -dEPSCrop \
-sOutputFile=$PNG $EPS
echo Converting into PDF version ...
ps2pdf -dEPSCrop $SIZEPARMS $EPS
# done!
echo Done!