Forked from dsparks/Herfindahl–Hirschman_Index.R
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March 1, 2013 16:44
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This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode charactersOriginal file line number Diff line number Diff line change @@ -0,0 +1,21 @@ doInstall <- TRUE # Change to FALSE if you don't want packages installed. toInstall <- c("plyr", "ggplot2") if(doInstall){install.packages(toInstall, repos = "http://cran.r-project.org")} lapply(toInstall, library, character.only = TRUE) ANES <- read.csv("http://www.oberlin.edu/faculty/cdesante/assets/downloads/ANES.csv") head(ANES) ANES$PID3 <- factor(ANES$pid7) # Convert to three-level Party ID: levels(ANES$PID3) <- c("Dem", "Dem", "Dem", "Ind", "Rep", "Rep", "Rep") # Using plyr to estimate the "Effective numbers of parties" by year and region ENpid3 <- ddply(.data = ANES, .progress = "text", .variables = .(year, south), summarize, # Calculate an inverse HHI invHHI = sum(table(PID3))^2 / sum(table(PID3)^2)) zp1 <- ggplot(ENpid3) zp1 <- zp1 + geom_line(aes(x = year, y = invHHI, colour = factor(south))) zp1 <- zp1 + ggtitle("Effective Number of Parties-in-the-Electorate") print(zp1)