data.table j=list(var) slower than j=var

[tdhock]

@Anirban166 @DorisAmoakohene would be good to translate Rdatatable/data.table#712 to atime

[DorisAmoakohene]

@tdhock I tried this issue and I keep on getting this error

Error: object 'DT' not found

I have my DT defined, but looks like is not able to run in the setup

This is my atime code

result.withby <- atime::atime(
  N = 1:1e7,
  setup = {
    DT <- data.table(x=rep(N, 2L), y=1L)
    dd <- data.table(x=N,key="x")
  },
  expr.list = list(
    ans1 <- DT[, .N, by=x],
    ans2 <- DT[, list(N = .N), by=x],
    de <- dd[dd,1,by=.EACHI],
    df <- dd[dd,list(1),by=.EACHI],
    dg <- dd[dd,x,by=.EACHI],
    dh <- dd[dd,list(x),by=.EACHI]
  )
)

[tdhock]

It is normal to get that error about DT not found.
expr.list should be a list of un-evaluated expressions, see ?atime man page and examples.
I'm not sure you need to use expr.list at all here though.

[DorisAmoakohene]

@tdhock this is the result for this with this code

result.withby <- atime::atime(
  N =unique(as.integer(1:1e9)),
  setup = {
    DT <- data.table(x=rep(N, 2L), y=1L)
    dd <- data.table(x=N,key="x")
  },
  seconds.limit = 0.001,
  
    ans1 = DT[, .N, by=x],
    ans2 = DT[, list(N = .N), by=x],
    de = dd[dd,1,by=.EACHI],
    df =  dd[dd,list(1),by=.EACHI],
    dg = dd[dd,x,by=.EACHI],
    dh = dd[dd,list(x),by=.EACHI]
  
)

[tdhock]

can you please increase seconds.limit?
and also maybe only include the three examples here Rdatatable/data.table#712 (comment)