c(2, 3, 5)
length(c("aa", "bb", "cc", "dd", "ee"))
n = c(2, 3, 5)
s = c("aa", "bb", "cc", "dd", "ee")
c(n, s)
a = c(1, 3, 5, 7)
b = c(1, 2, 4, 8)
5 * a
a + b
a - b
a * b
u = c(10, 20, 30)
v = c(1, 2, 3, 4, 5, 6, 7, 8, 9)
u + v
a[0]
a[1]
b
b[0]
b[1]
b
b[-2]
b[20]
b[c(2, 3)]
a
a[c(1, 4)]
a
a[1:4]
a[1:3]
a[c(FALSE, TRUE, FALSE, TRUE)]
v = c("Mary", "Sue")
names(v)
names(v) = c("First", "Last")
names(v)
v["First"]
A = matrix(
    c(2, 4, 3, 1, 5, 7),
    nrow=2,
    ncol=3,
    byrow=TRUE)
A
A[1, 3]
A[2,]
A[, c(1, 3)]
dimnames(A) = list(
    c("row1", "row2"),
    c("col1", "col2", "col3"))
A
A["row2", "col3"]
B = matrix(
    c(2, 4, 3, 1, 5, 7),
    nrow=3,
    ncol=2)
B
t(B)
C = matrix(
    c(7, 4, 2),
    nrow=3,
    ncol=1)
C
cbind(B, C)
D = matrix(
    c(6, 2),
    nrow=1,
    ncol=2)
D
B
BD = rbind(B, D)
BD
c(B)
n = c(2, 3, 5)
s = c("aa", "bb", "dd", "ee")
b = c(TRUE, FALSE, TRUE, FALSE, FALSE)
x = list(n, s, b, 3)
x
x[2]
x[1]
x[2]
x[[2]]
x[[2]][1] = "DORP"
x[[2]]
s
v = list(bob=list("Bob", "Johnson", c(2, 3, 5)), john=list("John", "Smythe", c(1, 4, 6)))
v
v["bob"]
v[["bob"]]
v[["bob"]][[1]]
v[["bob"]][[1]] = "Robert"
v["bob"]
v$bob
v$john
v$john[1]
v$john[[1]]
v$john[[1]] = 
"Johnny"
v$john
attach(v)
bob
detach(v)
bob
mtcars
n = c(2, 3, 5)
s = c("aa", "bb", "cc")
b = c(TRUE, FALSE, TRUE)
df = data.frame(n, s, b)
mtcars["Mazda RX4", "mpg"]
nrow(mtcars)
ncol(mtcars)
ncol(s)
s
B
nrow(B)
ncol(B)
head(mtcars)
q()
s
q()
mtcars[[[9]]
mtcars[[9]]
mtcars[["am]]
mtcars[["am"]]
mtcars$am
mtcars[1]
head(mtcars[1])
mtcars["mpg"]
mtcars[c("mpg", "hp")]
mtcars[c("mpg", "hp")][1]
mtcars[c("mpg", "hp")][[1]]
mtcars[24,]
mtcars["Camaro Z28",]
mtcars[c("Datsun 710", "Camaro Z28")]
mtcars[c("Datsun 710", "Camaro Z28",)]
mtcars[c("Datsun 710", "Camaro Z28"),]
L = mtcars$am == 0
L
mtcars[L,]
mtcars[L,]
mtcars[L,]$mpg
library(gdata)
library(foreign)
help(read.mtp)
mydata = read.table("mydata.txt")
mydata
mydata = read.csv("mydata.csv")
mydata
getwd()
q()