# the matrix function can be used for data sets with only numeric variables

data <- matrix(scan(),ncol=2,byrow=TRUE)        
 1  1
 2  1
 3  1
 5  2
 3  2
 4  2
 6  3
 7  3
 5  3 

data

tastetest <- data.frame(data)
colnames(tastetest) <- c("taste","treat")

rm(data)   # remove unneeded objects

 # we must make sure that treat is a factor, not numeric
tastetest$treat <- as.factor(tastetest$treat)

boxplot(taste ~ treat, data = tastetest, main = "Taste test data")

tastetest.lm <- lm(taste ~ treat, data = tastetest)

anova(tastetest.lm)
summary(tastetest.lm)

x11()               # opens a new graphics window on multiple operating systems
# windows()         # opens a new graphics window under Windows operating system

par(mfrow=c(2,2))  
plot(tastetest.lm)
par(mfrow=c(1,1))  



# ------------------------------------------------------------------------------------

# Alternatively, treatment can be defined as a character variable using the scan function:

data <- scan(what = list(taste=0,treat=""), multi.line=F)   
 1  1
 2  1
 3  1
 5  2
 3  2
 4  2
 6  3
 7  3
 5  3 

data

tastetest <- data.frame(data)