CODEWITHSUNDEEP
rchar
Peach212
Peach212

Reputation: 21

How do you create a modified character vector from a pre-existing character vector in R?

I'm very new to R and I know this is a really simple question but I can't seem to figure it out.

I am given the character vector more.colors:

more.colors <- c("red", "yellow", "blue", "green", "magenta", "cyan")

And I have to use the more.colors vector, rep() and seq() to create the vector:

"red" "yellow" "blue" "yellow" "blue" "green"
"blue" "green" "magenta" "green" "magenta" "cyan"

So far all I have is c(more.colors[1:3], more.colors[2:3], more.colors[4], more.colors[3:4], more.colors[5], more.colors[4:5], more.colors[6]) which doesn't use rep() or seq().

Any help would be much appreciated!

Upvotes: 1

Views: 111

Answers (2)

Allan Cameron
Allan Cameron

Reputation: 173793

If you look at the sequence of the target vector, it is equivalent to more.colors[c(1, 2, 3, 2, 3, 4, 3, 4, 5, 4, 5, 6)], so this is really an exercise in using rep and seq to get the sequence c(1, 2, 3, 2, 3, 4, 3, 4, 5, 4, 5, 6).

I think this exercise is getting you to use the two different methods of rep; that is, you can repeat each element of the vector n times if you do each = n, and you can get the whole vector to repeat n times if you pass times = n

So the solution here is to repeat the sequence "1 to 3" four times, and add it to the sequence "0 to 4" where each element is repeated three times

more.colors[rep(seq(0, 3), each = 3) + rep(seq(1, 3), times = 4)]
#> [1] "red"     "yellow"  "blue"    "yellow"  "blue"    "green"   "blue"   
#> [8] "green"   "magenta" "green"   "magenta" "cyan"

Upvotes: 2

peter
peter

Reputation: 786

This would work:

new.colors <- c()

for (i in 1:(length(more.colors)-2)) {
  new.colors <- c(new.colors, more.colors[i:(i+2)])
}

Upvotes: 1

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