Creating a sequence of vector and replacing some elements

Question

I want this as my desired vector

0,2,3,0,5,0,7,0,0

I used these commands but didnt succeed.

b <- c(1:9)
b
x <- replace(b,b==c(1,4,6,8,9),c(0,0,0,0,0)
x
g <- (gsub(c(1,4,6,8,9),c(0,0,0,0,0),b))

Saw this before applying these commands.

Answer 1

When we are comparing b with the vector using == we are comparing elementwise so b[1] is compared with 1, b[2] is compared with 4 and so on. Since length(c(1,4,6,8,9)) is shorter than length(b) those values are recycled to match the length of b.

b == c(1,4,6,8,9)
#[1]  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE

Warning message: In b == c(1, 4, 6, 8, 9) : longer object length is not a multiple of shorter object length

To compare multiple values we need %in%

b %in% c(1,4,6,8,9)
#[1]  TRUE FALSE FALSE  TRUE FALSE  TRUE FALSE  TRUE  TRUE

so that we can use replace like

replace(b,b %in% c(1,4,6,8,9),c(0, 0, 0, 0, 0))
#[1] 0 2 3 0 5 0 7 0 0

However, replace can accept vector of positions so we can directly do

replace(b, c(1,4,6,8,9), 0)
#[1] 0 2 3 0 5 0 7 0 0