# ReadingIndep Example -- reading-indep.R source code.

# Read data from input file.
scores <- read.table("reading-indep.txt", header=TRUE)
std <- scores$Score[scores$Method == "STD"]
new <- scores$Score[scores$Method == "NEW"]

# Print data.
cat("Scores of students taught by standard teaching method:\n")
print(std)
cat("Score of students taught by new teaching method:\n")
print(new)

# Perform independent two-sample t-test, assuming equal variances.
ttest <- t.test(std, new, alternative="two.sided", 
   paired=FALSE, var.equal=TRUE, conf.level=0.95)
print(ttest)

# Perform independent two-sample t-test, not assuming equal variances.
ttest <- t.test(std, new, alternative="two.sided", 
   paired=FALSE, var.equal=FALSE, conf.level=0.95)
print(ttest)

# Perform F-test to test null hypothesis that variances 
# of two methods are the same.
vartest <- var.test(std, new)
print(vartest)