Unnest: Fast Unnesting of Data Tables — dt

Quickly unnest data tables, particularly those nested by dt_nest().

dt_unnest(dt_, col, keep = TRUE)

Arguments

dt_: the data table to unnest
col: the column to unnest
keep: whether to keep the nested column, default is TRUE

Examples


library(data.table)
dt <- data.table(
  x = rnorm(1e5),
  y = runif(1e5),
  grp = sample(1L:3L, 1e5, replace = TRUE)
)

nested <- dt_nest(dt, grp)
dt_unnest(nested, col = data)
#> Key: <grp>
#>           grp          x          y                  data
#>         <int>      <num>      <num>                <list>
#>      1:     1  1.0132525 0.02937715 <data.table[33351x2]>
#>      2:     1  1.3222125 0.17566096 <data.table[33351x2]>
#>      3:     1  0.5065119 0.06658542 <data.table[33351x2]>
#>      4:     1 -0.9279822 0.55996602 <data.table[33351x2]>
#>      5:     1  0.7179084 0.85645944 <data.table[33351x2]>
#>     ---                                                  
#>  99996:     3  0.5534343 0.82439307 <data.table[33394x2]>
#>  99997:     3 -0.5466994 0.59113375 <data.table[33394x2]>
#>  99998:     3  0.0279944 0.50978427 <data.table[33394x2]>
#>  99999:     3  1.9397046 0.40044357 <data.table[33394x2]>
#> 100000:     3  1.4679262 0.38763369 <data.table[33394x2]>