[R] Create a numeric series in an efficient way

[Bert Gunter]

"If you want a much more compact solution that handles arbitrary pairs of
"what to copy", number_of_copies, you can write a function  that evaluates
two arguments at a time or takes two vectors as arguments like this one I
wrote quickly and crudely:"

Please! -- The "times" argument of rep can be a vector that does exactly this:

times
an integer-valued vector giving the (non-negative) number of times to
repeat each element if of length length(x), or to repeat the whole
vector if of length 1.

In future, please read the Help files carefully before dispensing such "advice."

-- Bert


On Thu, Jun 13, 2024 at 7:04 PM <avi.e.gross using gmail.com> wrote:
>
> For the particular example you asked for, consider the "each" you can use
> with rep()
>
> rep(1:13, each=84)
>
> This is what it does for a shorter version of 4 each:
>
> > rep(1:13, each=4)
>  [1]  1  1  1  1  2  2  2  2  3  3  3  3  4  4  4  4  5  5  5  5  6  6  6  6
> 7  7  7  7  8  8  8  8  9  9  9  9 10 10 10 10
> [41] 11 11 11 11 12 12 12 12 13 13 13 13
>
>
> For another variant, make 84 copies of 1:13 and sort that as you happen to
> want the numbers in order.
>
> sort(rep(1:13, each=84))
>
> The output is the same.
>
> If you want a much more compact solution that handles arbitrary pairs of
> "what to copy", number_of_copies, you can write a function  that evaluates
> two arguments at a time or takes two vectors as arguments like this one I
> wrote quickly and crudely:
>
> rep_many <- function(items, counts) {
>   result <- c()
>   for (index in 1:length(items)) {
>     result <- c(result, rep(items[index], counts[index]))
>   }
>   return(result)
>   }
>
> rep_many(1:13, rep(84,13))
>
>
> The same ideas can be used using a data.frame or functional programming
> methods but the above is simple enough to flexibly create two vectors
> specifying how much of each.
>
> You said you found a solution, so you may want to share what you chose
> already.
>
>
>
>
> -----Original Message-----
> From: R-help <r-help-bounces using r-project.org> On Behalf Of Francesca PANCOTTO
> via R-help
> Sent: Thursday, June 13, 2024 10:42 AM
> To: r-help using r-project.org
> Subject: [R] Create a numeric series in an efficient way
>
> Dear Contributors
> I am trying to create a numeric series with repeated numbers, not difficult
> task, but I do not seem to find an efficient way.
>
> This is my solution
>
> blocB <- c(rep(x = 1, times = 84), rep(x = 2, times = 84), rep(x = 3, times
> = 84), rep(x = 4, times = 84), rep(x = 5, times = 84), rep(x = 6, times =
> 84), rep(x = 7, times = 84), rep(x = 8, times = 84), rep(x = 9, times =
> 84), rep(x = 10, times = 84), rep(x = 11, times = 84), rep(x = 12, times =
> 84), rep(x = 13, times = 84))
>
> which works but it is super silly and I need to create different variables
> similar to this, changing the value of the repetition, 84 in this case.
> Thanks for any help.
>
>
> F.
>
>         [[alternative HTML version deleted]]
>
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>
> ______________________________________________
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.