color1

ggd2g1.r

#######################################################
# Example 4: Casting/Melting with custom functions    #
#######################################################

#Let's first define a function, SE, to represent the standard error of a
#variable:
library(gridExtra)
library(ggplot2)
SE <- function(X) {
(sd(X, na.rm=TRUE)/ sqrt(length(X)-1)  )
}

ANES <- read.csv("http://www.oberlin.edu/faculty/cdesante/assets/downloads/ANES.csv")
head(ANES)
ANES$caseid <- 1:dim(ANES)[1]

TRUST <-melt(ANES, id=c("year", "dems"), na.rm=TRUE)
head(TRUST)
TRUST <- TRUST[TRUST$variable=="trust",]

#first thing I'll cast are the means of the "trust" variable over
#time, based on the respodnent's two-party identification

MEANS <- cast(TRUST, year+dems~variable, mean, na.rm=TRUE)
head(MEANS)

SEs <- cast(TRUST, year+dems~variable, SE)
head(SEs)

TRUST.plot <- cbind(MEANS$year,MEANS$dems,SEs$dems, MEANS$trust, SEs$trust,
        (MEANS$trust - 1.96* SEs$trust), (MEANS$trust + 1.96* SEs$trust) )
TRUST.plot
TRUST.plot <- TRUST.plot[complete.cases(TRUST.plot),]

colnames(TRUST.plot) <- c("year", "dems", "dems.2", "means",
                            "SE", "lows", "highs")

DF <- as.data.frame(TRUST.plot)

T1 <- ggplot(data = DF) + geom_pointrange(aes(x = year, y = means,
                             ymin = lows, ymax = highs, colour=factor(dems)) )
 T1 <- T1  + labs(title="geom_pointrange, T1")
T1