R help - Mar 2021 - "global parameter" warning using data.table in package.

Hi,

  I am converting a couple of functions into a R-package. Many of the
functions use data.table.
  I have two questions using data.table in my own package.
  Normally I would put each question in separate emails but I think they
might be connected.

First question is short and I think the answer is yes.
1. Do I always need to prefix data.table each time I use something from
that package?
Eg. DT <-
data.table::data.table(x=rep(c("b","a","c"),each=3),
y=c(1,3,6),
v=1:9)

Second question is longer.
2.  In this small example code:
hello <- function() {
  DT <-
data.table::data.table(x=rep(c("b","a","c"),each=3),
y=c(1,3,6),
v=1:9)
  DT[, .(sum(v))]
}

I get these warnings from R CMD check:
hello: no visible global function definition for ?.?
hello: no visible binding for global variable ?v?
Undefined global functions or variables:
  . v

According to: vignette("datatable-importing", package =
"data.table")
The solution is
hello <- function() {
  v <- NULL
  . <- NULL

And it works but looks a bit weird.
Is there a better solution?

Regards
Martin

	[[alternative HTML version deleted]]

Please ignore my previous email. I just found the R-package-devel mailing
list.

On Fri, 5 Mar 2021 at 14:25, Martin M?ller Skarbiniks Pedersen <
traxplayer at gmail.com> wrote:
> Hi,
>
>   I am converting a couple of functions into a R-package. Many of the
> functions use data.table.
>   I have two questions using data.table in my own package.
>   Normally I would put each question in separate emails but I think they
> might be connected.
>
> First question is short and I think the answer is yes.
> 1. Do I always need to prefix data.table each time I use something from
> that package?
> Eg. DT <-
data.table::data.table(x=rep(c("b","a","c"),each=3),
y=c(1,3,6),
> v=1:9)
>
> Second question is longer.
> 2.  In this small example code:
> hello <- function() {
>   DT <-
data.table::data.table(x=rep(c("b","a","c"),each=3),
y=c(1,3,6),
> v=1:9)
>   DT[, .(sum(v))]
> }
>
> I get these warnings from R CMD check:
> hello: no visible global function definition for ?.?
> hello: no visible binding for global variable ?v?
> Undefined global functions or variables:
>   . v
>
> According to: vignette("datatable-importing", package =
"data.table")
> The solution is
> hello <- function() {
>   v <- NULL
>   . <- NULL
>
> And it works but looks a bit weird.
> Is there a better solution?
>
> Regards
> Martin
>

-- 
Til uvedkommende, der l?ser med: Der er ingen grund til at l?se min
mail. Jeg har intet at g?re med FARC, al-Jihad, al-Qaida, Hamas, Hizb
al-Mujahidin eller ETA. Jeg har aldrig gjort Zakat, g?r ikke ind for
Istishad, har ikke lavet en bilbombe eller kernev?ben og jeg ved
d?rligt nok, hvad Al Manar og ????? betyder.  Men tak for den udviste
interesse.

Leve Ligemageriet!
Styrk p?belv?ldet!
Bevar misundelsesafgifterne og cafepengene!
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	[[alternative HTML version deleted]]

I believe these questions belong on r-package-devel, not here.

Bert Gunter

"The trouble with having an open mind is that people keep coming along and
sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )


On Fri, Mar 5, 2021 at 5:25 AM Martin M?ller Skarbiniks Pedersen <
traxplayer at gmail.com> wrote:
> Hi,
>
>   I am converting a couple of functions into a R-package. Many of the
> functions use data.table.
>   I have two questions using data.table in my own package.
>   Normally I would put each question in separate emails but I think they
> might be connected.
>
> First question is short and I think the answer is yes.
> 1. Do I always need to prefix data.table each time I use something from
> that package?
> Eg. DT <-
data.table::data.table(x=rep(c("b","a","c"),each=3),
y=c(1,3,6),
> v=1:9)
>
> Second question is longer.
> 2.  In this small example code:
> hello <- function() {
>   DT <-
data.table::data.table(x=rep(c("b","a","c"),each=3),
y=c(1,3,6),
> v=1:9)
>   DT[, .(sum(v))]
> }
>
> I get these warnings from R CMD check:
> hello: no visible global function definition for ?.?
> hello: no visible binding for global variable ?v?
> Undefined global functions or variables:
>   . v
>
> According to: vignette("datatable-importing", package =
"data.table")
> The solution is
> hello <- function() {
>   v <- NULL
>   . <- NULL
>
> And it works but looks a bit weird.
> Is there a better solution?
>
> Regards
> Martin
>
>         [[alternative HTML version deleted]]
>
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>
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