####  "All the examples" from  ./R-intro.texi
####  -- in a way that this should be(come) an executable script.

## 2. Simple Manipulations
x <- c(10.4, 5.6, 3.1, 6.4, 21.7)
1/x

# put vectors together
y <- c(x, 0, x)

#Perform operations on vectors
sqrt(x)

###--  2.3 .. regular sequences
1:30

n <- 10

1:n-1
1:(n-1)
30:1

seq(2,10)

s3 <- seq(-5, 5, by=.2) 
s4 <- seq(length=51, from=-5, by=.2)
all.equal(s3,s4)

s5 <- rep(x, times=5)
s6 <- rep(x, each=5)

temp <- x > 13

z <- c(1:3,NA);  ind <- is.na(z)

0/0
Inf - Inf

labs <- paste(c("X","Y"), 1:10, sep="")
labs

x <- c(x, 9:12)# long enough:
x[1:10]

y <- x[-(1:5)]
y

fruit <- c(5, 10, 1, 20)
names(fruit) <- c("orange", "banana", "apple", "peach")
 fruit

lunch <- fruit[c("apple","orange")]
 lunch

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

z <- 0:9
digits <- as.character(z)
digits
d <- as.integer(digits)
all.equal(z, d)

alpha <- 10*(1:10)
alpha <- alpha[2 * 1:5]
alpha

winter <- data.frame(temp = c(-1,3,2,-2), cat = rep(c("A","B"), 2))
winter

###------------ Ordered and unordered factors --------
state <- c("tas", "sa",  "qld", "nsw", "nsw", "nt",  "wa",  "wa",
           "qld", "vic", "nsw", "vic", "qld", "qld", "sa",  "tas",
           "sa",  "nt",  "wa",  "vic", "qld", "nsw", "nsw", "wa",
           "sa",  "act", "nsw", "vic", "vic", "act")
statef <- factor(state)
statef

levels(statef)

incomes <- c(60, 49, 40, 61, 64, 60, 59, 54, 62, 69, 70, 42, 56,
             61, 61, 61, 58, 51, 48, 65, 49, 49, 41, 48, 52, 46,
             59, 46, 58, NA)

incmeans <- tapply(incomes, statef, mean, na.rm=T) # similar to the 'aggregate' function)
incmeans

stderr <- function(x) sqrt(var(x)/length(x))

incster <- tapply(incomes, statef, stderr)
incster

### apply functions
# there are a family of apply functions
X<-matrix(rnorm(30), nrow=5, ncol=6)
X
apply(X,2,sum) # sums columns
apply(X,1,mean) # row means

# apply
A<-matrix(1:9, 3,3)
B<-matrix(4:15, 4,3)
C<-matrix(8:10, 3,2)
MyList<-list(A,B,C) # display the list

lapply(MyList,"[", ,1) # Extract first column of each matrix
lapply(MyList,"[", 1,) # Extract first row of each matrix

sapply(MyList, mean) # return the mean of each list object

###--- @chapter 6. Lists and data frames

Lst <- list(name="Fred", wife="Mary", no.children=3,
            child.ages=c(4,7,9))
Lst$name
Lst$wife
Lst$child.ages[1]
x <- "name" ; Lst[[x]]

## @section  6.2  Constructing and modifying lists

##<init>
Mat <- cbind(1, 2:4)
##</init>
Lst$matrix <- Mat
Lst
## @section  6.3  Data frames

accountants <- data.frame(home=statef, loot=incomes)
## MM: add the next lines to R-intro.texi !
accountants
str(accountants)

## ..........

# do some basic plots
hist(accountants$loot)
plot(accountants$home, accountants$loot,xlab="State", ylab="Income") # produces a boxplot as 'home' is a factor