setwd('/home/Hornik/tmp/')
x <- c("Misha", "Alice", "Akos", "Niko")
x
toupper(x)
tolower(x)
y <- tolower(x)
y
substring(y[1], 1:5, 1:5)
substring(y[3], 1:5, 1:5)
strsplit(y, NULL)
z <- strsplit(y, NULL)
z
typeof(z)
length(z)
z
z
z[c(1, 4)]
z
z[1]
typeof(z[1])
length(z[1])
n <- 1 : 5
n
n[1]
z
z[1]
z[[1]]
z[1]
z
z[[1]]
z[[1]][1]
z
z
names(z) <- x
z
z$Misha
z["Misha"]
z[["Misha"]]
z$Misha
n <- "Misha"
z[[n]]
z$n
list()
list(1, 2, 3)
list(5)
list(FALSE, 1:2, x)
vector("list", 5)
vector("logical", 5)
x
as.list(x)
w <- list(1, 1:2, 1:3, 1:4)
w
length(w)
for(e in w) print(length(e))
lengths(w)
w
sum(w)
sums(w)
vapply(w, sum, 0)
lapply(w, sum)
unlist(lapply(w, sum))
w
lengths(w)
vapply(w, length, 0)
lapply(w, length)
unlist(lapply(w, length))
w
3 ^ 2
sq <- function(x) x ^ 2
sq(3)
lapply(w, sq)
lapply(w, function(x) x ^ 2)
lapply(w, `^`, 2)
w
lapply(lapply(w, `^`, 2), sum)
lapply(w, function(x) sum(x ^ 2))
x
y
z
lapply(z, function(e) e == "a")
lapply(lapply(z, function(e) e == "a"), sum)
vapply(lapply(z, function(e) e == "a"), sum, 0)
vapply(z, function(e) sum(e == "a"), 0)
z
substring(y, 1, 1)
sum(substring(y, 1, 1) == "a")
z
vapply(z, function(e) e[1L] == "a", 0)
vapply(z, function(e) e[1L] == "a", NA)
z
vapply(z, function(e) e[length(e)] %in% c("a", "e", "i", "o", "u"), NA)
z
vapply(z, function(e) any(e == "a"), 0)
y
grep("a", y)
grepl("a", y)
vapply(z, function(e) any(e == "a"), NA)
vapply(strsplit(y, NULL), function(e) any(e == "a"), NA)
grepl("a", y)
y
grepl("^a", y)
grepl("o$", y)
vapply(z, function(e) e[length(e)] %in% c("a", "e", "i", "o", "u"), NA)
grep("[aeiou]$", y)
grepl("[aeiou]$", y)
y
y[1]
sub("m", "h", y[1])
sub("m", "sh", y[1])
sub("m", "sh", y)
gsub("a", "???", y)
y
sub("a", "???", "anna")
gsub("a", "???", "anna")
y
y
sub("[aeiou]", "", y)
gsub("[aeiou]", "", y)
nchar(gsub("[aeiou]", "", y))
nchar(y) - nchar(gsub("[aeiou]", "", y))
y
y
y == "akos"
y %in% c("akos", "alice")
match(y, c("akos", "alice")
)
y
grepl("[aeiou].[aeiou]", y)
grepl("[aeiou]..[aeiou]", y)
grepl("a.*s", y)
grepl("a.*o", y)
grepl("a.+o", y)
s <- "eeee"
s
grepl("e[^e]e", s)
y
grepl("ce", y)
grepl("[ae][sl]", y)
grepl("[ae][^sl]", y)
grepl("li|ko", y)
grepl("(li|ko)e", y)
grepl("(li|ko)c", y)
y
gsub("li|ko", "", y)
gsub("li|ko", "\\1\\1", y)
gsub("(li|ko)", "\\1\\1", y)
gsub("(li|ko)", "<\\1><\\1>", y)
gsub("(li|ko)", "<\\1>", y)
gsub("(li|ko)", "*\\1*", y)
gsub("(li|ko)", "__\\1**", y)
gsub("(li|ko)", "__\\1__", y)
for(i in 1 : 10) print(i)
for(i in 1 : 10) { if(i == 3) next; print(i) }
for(i in 1 : 10) { if(i == 3) break; print(i) }
add <- function(x, y) x + y
add(1, 2)
pow <- function(x, y) x ^ y
pow(3, 2)
pow
pow(y = 2, 3)
seq
seq.default
args(seq.default)
seq(1, 9, , 3)
seq(1, 9, len = 3)
pow
pow(3, )
pow(3)
pow <- function(x, y) x ^ y
pow <- function(x, y = 1) x ^ y
pow(3)
args(pow)
pow(y = 2, 3)
pow(y = 2)


Fib1 <- function(n) {

Fib1(1)
Fib1(2)
Fib1(3)
Fib1(5)
Fib1(7)
Fib1(100)
Fib1(10)
Fib1(15)
Fib1(20)
Fib1(25)
Fib1(30)
Fib1(40)
Fib1(50)
Fib1(100)
Fib1(100)
Fib2 <- function(n) {
Fib2(1)
Fib2(2)
Fib2(3)
Fib2(5)
Fib2(10)
Fib2(15)
Fib2(20)
Fib1(50)
Fib2(25)
Fib2(30)
Fib2(25)
Fib2(30)
Fib2(32)
Fib2(33)
Fib2(34)
Fib1(100)
plot(1:100, Fib1(100))
plot(1:100, log(Fib1(100)))
Fib3 <- function(n) {

Fib3(10)
Fib3(20)
Fib3(30)
Fib3(100)
system.time(Fib1(100))
system.time(Fib1(200))
system.time(Fib1(500))
system.time(Fib1(1000))
system.time(Fib3(1000))
system.time(Fib1(10000))
system.time(Fib3(10000))
q()