x <- c(1,3,4,5)
x
length(x)
mode(x)
names(x)
y <- c( c(2,3), c(1,-6))
y
rep(NA,6)
rep(x, 3)
rep(x, c(1,2,2,3))
1:13
-3:6
1.1:5
4:-5

seq(-1,2, 0.5)
seq(-1,2, length=12)
seq(1, by=0.5, length=12)

matr <- rep(1:4, rep(3,4))
matr
dim(matr) <- c(3,4)
matr
matr2 <- seq(-2,2,length=25)
matr2
dim(matr2) <- c(5,5)
matr2

matr3 <- rbind(c(1,2,-1), c(-3,1,5))
matr3
matr4 <- cbind(c(1,2,-1), c(-3,1,5))
matr4
matr5 <- cbind(c(1,2,-1), c(-3,3,2,0))
matr5

matr6 <- cbind(matr, matr4)
matr6
matr6 <- cbind(matr, matr3)
matr7 <- matrix(1:28, nrow=7, ncol=4)
matr7
matr8 <- matrix(-5:6, ncol=3, byrow=T)
matr8
matrix(1:23, nrow=7, ncol=4)
matrix(1:23, nrow=7)

matr8
length(matr8)
dim(matr8)
mode(matr8)
dimnames(matr8)
dimnames(matr8) <- list(c("A","B","C","D"), c("K1","K2","K3"))
matr8

arr1  <- array( c(2:9,12:19,112:119), dim=c(2,4,3))
arr1
length(arr1)
mode(arr1)
dim(arr1)
dimnames(arr1)

group1 <- c(rep(1,11), rep(2,17))
group2 <- c(23,45,67,76,-8,3.5,2.19,4)
groups <- list(case=group1, control=group2, descrip="An example")
groups
groups$case
groups$control
groups[[1]]
groups[[2]]
groups[[2]][1:2]
length(groups)
mode(groups)
names(groups)

gender <- c("male", "female", "male", "male", "female", "female", "male")
gender
factor(gender)
intensity <- factor(c("Hi", "Med", "Lo", "Hi", "Hi", "Lo"),levels=c("Hi","Lo"))
intensity
levels(intensity)
intensity <- factor(c("Hi", "Med", "Lo", "Hi", "Hi", "Lo"),levels=c("Hi","Lo"), labels=c("HighDose", "LowDose"))
intensity

intensity <- ordered(c("Hi", "Med", "Lo", "Hi", "Hi", "Lo"),levels=c("Lo", "Med", "Hi"))
intensity

fact <- rnorm(10)
fact1 <- cut(fact, breaks=c(-5,-1,1,2,4))
fact1
fact2 <- cut(fact, breaks=5)
fact2

length(intensity)
mode(intensity)
names(intensity)
levels(intensity)
class(intensity)

library("faraway")
test <- sample(1:900, 13)
solder[test,]

my.logic<-sample(c(T,F),size=20,replace=T)
my.logic
my.complex<-rnorm(20)+runif(20)*1i
my.complex
my.numeric<-rnorm(20)
my.numeric
my.matrix<-matrix(rnorm(40),ncol=2)
my.matrix
my.dataframe<-data.frame(my.logic,my.complex,my.numeric,my.matrix)
my.dataframe
my.dataframe2 <- cbind(1, my.dataframe)
my.dataframe2
length(my.dataframe)
dim(my.dataframe)
is.data.frame(my.dataframe)
is.list(my.dataframe)
is.matrix(my.dataframe)
is.vector(my.dataframe)
names(my.dataframe)

attach(my.dataframe)
my.logic
my.complex