R source code that is used for producing the graphics used in the blog entry titled "Results of the survey: Why don’t we have secondary school textbooks with source code in them?"

textbook.R

## textbook.R
## Tested on:
## R version 2.15.1 (2012-06-22) -- "Roasted Marshmallows"

library(ggplot2)
library(car)

setwd("~/Documents/programming/R/")

textbook <- read.csv("textbook.csv", na.strings = "")

isGreat <- textbook$Do.you.think.it.would.be.great.if.secondary.school.students.had.such.textbooks
isUsed <- textbook$Have.you.ever.used.such.a.book.during.YOUR.secondary.education
isCurrent <- textbook$Do.you.know.secondary.education.textbook.s...currently.in.use..with.source.code.samples.at.the.end.of.each.chapter

isGreat <- recode(isGreat, "NA='N/A'")
isUsed <- recode(isUsed, "NA='N/A'")
isCurrent <- recode(isUsed, "NA='N/A'")

cPalette1 <- c('black','red','blue')
cPalette2 <- c('red','blue')

png('isGreat.png')
p <- qplot(isGreat, geom="bar", fill=factor(isGreat),
           main="   Do you think it would be great if secondary
  school students had textbooks with source code?",
           xlab = "")
p + scale_fill_manual(values=cPalette1) +
    theme(legend.title=element_blank()) +
    theme(axis.text=element_text(family = "Source Code Pro",
                                  face="bold", size = 13)) +
    theme(plot.title=element_text(family = "Source Code Pro",
                                  face="bold", size = 13))
dev.off()

png('isUsed.png')
p <- qplot(isUsed, geom="bar", fill=factor(isUsed),
           main="Have you ever used such a book during your
secondary education?",
           xlab = "")
p + scale_fill_manual(values=cPalette2) +
    theme(legend.title=element_blank()) +
    theme(axis.text=element_text(family = "Source Code Pro",
                                  face="bold", size = 13)) +
    theme(plot.title=element_text(family = "Source Code Pro",
                                  face="bold", size = 14))
dev.off()

png('isCurrent.png')
p <- qplot(isCurrent, geom="bar", fill=factor(isUsed),
           main="  Do you know secondary education textbook(s)
(currently in use) with source code samples
at the end of each chapter?",
           xlab = "")
p + scale_fill_manual(values=cPalette2) +
    theme(legend.title=element_blank()) +
    theme(axis.text=element_text(family = "Source Code Pro",
                                  face="bold", size = 13)) +
    theme(plot.title=element_text(family = "Source Code Pro",
                                  face="bold", size = 14))
dev.off()