## -----------------------------------------------------------------------------
nrow


## -----------------------------------------------------------------------------
dim


## -----------------------------------------------------------------------------
nrow()


## -----------------------------------------------------------------------------
m <- matrix(1:6, nrow=2, ncol=3, byrow=TRUE)
nrow(m)


## -----------------------------------------------------------------------------
nrow(x=m)


## -----------------------------------------------------------------------------
f <- function() {
	return('hello')
}


## -----------------------------------------------------------------------------
#inspect 
f
#use 2 times
f()
f()


## -----------------------------------------------------------------------------
f <- function(name) {
	x <- paste("hello", name)
	return(x)
}

f('Jasmin')


## -----------------------------------------------------------------------------
f <- function(name) {
	paste("hello", name)
}

f("Sviatoslav")


## -----------------------------------------------------------------------------
frs <- function(n) {
	s <- sample(letters, n, replace=TRUE)
	r <- paste0(s, collapse="")
	return(r)
}


## -----------------------------------------------------------------------------
set.seed(0)
frs(5)
frs(5)
x <- frs(10)
x


## -----------------------------------------------------------------------------
sumsquare <- function(a, b) {
	d <- a + b
	dd <- d * d
	return(dd)
}


## -----------------------------------------------------------------------------
sumsquare(1,2)
x <- 1:3
y <- 5
sumsquare(x,y)


## -----------------------------------------------------------------------------
sumsquare(a=1, b=2)


## -----------------------------------------------------------------------------
sumsquare(a=1, d=2)


## -----------------------------------------------------------------------------
sumsquare(1:5)


## -----------------------------------------------------------------------------
sumsquareD <- function(a=0, b=1) {
	d <- a + b
	dd <- d * d
	return(dd)
}

sumsquareD(1:5, 2)


## -----------------------------------------------------------------------------
sumsquareD()


## -----------------------------------------------------------------------------
sumsquareD(5)


## -----------------------------------------------------------------------------
sumsquareD(b=3)


## -----------------------------------------------------------------------------
nunique <- function(x) { 
    length(unique(x)) 
}

data <- c("a", "b", "a", "c", "b")
nunique(data)


## -----------------------------------------------------------------------------
f1 <- function(x, y=10) {
	x * y
}

# f2 calls f1
f2 <- function(x, ...) {
	f1(x, ...)
}

f2(5)
f2(5, y=5)


## -----------------------------------------------------------------------------
f2(5, z=5)