The tibble S3 generic function pillar::glimpse() is implemented for
prt objects as well. Inspired by the output of str() when applied to
data.frames, this function is intended to display the structure of the
data in terms of columns, irrespective of how the data is organized in terms
of R objects. Similarly to format_dt(), the function providing the bulk
of functionality, glimpse_dt(), is exported such that implementing a
class specific pillar::glimpse() function for other classes that
representing tabular data is straightforward.
# S3 method for prt
glimpse(x, width = NULL, ...)
glimpse_dt(x, width = NULL)
str_sum(x)
# S3 method for prt
str(object, ...)
str_dt(x, ...)An object to glimpse at.
Width of output: defaults to the setting of the
width option (if finite)
or the width of the console.
Unused, for extensibility.
any R object about which you want to have some information.
Alongside a prt-specific pillar::glimpse() method, a str() method is
provided as well for prt objects. However, breaking with base R
expectations, it is not the structure of the object in terms of R objects
that is shown, but in the same spirit as pillar::glimpse() it is the
structure of the data that is printed. How this data is represents with
respect to R objects is abstracted away as to show output as would be
expected if the data were represented by a data.frame.
In similar spirit as format_dt() and glimpse_dt(), a str_dt() function
is exported which provides the core functionality driving the prt
implementation of str(). This function requires availability of a
head() function for any object that is passed and output can be
customized by implementing an optional str_sum() function.
cars <- as_prt(mtcars)
pillar::glimpse(cars)
#> Rows: 32
#> Columns: 11
#> Partitioning: [32] rows
#> $ mpg <dbl> 21.0, 21.0, 22.8, 21.4, 18.7, 18.1, 14.3, 24.4, 22.8, 19.2, 17.8…
#> $ cyl <dbl> 6, 6, 4, 6, 8, 6, 8, 4, 4, 6, 6, 8, 8, 8, 8, 8, 8, 4, 4, 4, 4, 8…
#> $ disp <dbl> 160.0, 160.0, 108.0, 258.0, 360.0, 225.0, 360.0, 146.7, 140.8, 1…
#> $ hp <dbl> 110, 110, 93, 110, 175, 105, 245, 62, 95, 123, 123, 180, 180, 18…
#> $ drat <dbl> 3.90, 3.90, 3.85, 3.08, 3.15, 2.76, 3.21, 3.69, 3.92, 3.92, 3.92…
#> $ wt <dbl> 2.620, 2.875, 2.320, 3.215, 3.440, 3.460, 3.570, 3.190, 3.150, 3…
#> $ qsec <dbl> 16.46, 17.02, 18.61, 19.44, 17.02, 20.22, 15.84, 20.00, 22.90, 1…
#> $ vs <dbl> 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0…
#> $ am <dbl> 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0…
#> $ gear <dbl> 4, 4, 4, 3, 3, 3, 3, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 4, 4, 4, 3, 3…
#> $ carb <dbl> 4, 4, 1, 1, 2, 1, 4, 2, 2, 4, 4, 3, 3, 3, 4, 4, 4, 1, 2, 1, 1, 2…
pillar::glimpse(cars, width = 30)
#> Rows: 32
#> Columns: 11
#> Partitioning: [32] rows
#> $ mpg <dbl> 21.0, 21.0, 22…
#> $ cyl <dbl> 6, 6, 4, 6, 8,…
#> $ disp <dbl> 160.0, 160.0, …
#> $ hp <dbl> 110, 110, 93, …
#> $ drat <dbl> 3.90, 3.90, 3.…
#> $ wt <dbl> 2.620, 2.875, …
#> $ qsec <dbl> 16.46, 17.02, …
#> $ vs <dbl> 0, 0, 1, 1, 0,…
#> $ am <dbl> 1, 1, 1, 0, 0,…
#> $ gear <dbl> 4, 4, 4, 3, 3,…
#> $ carb <dbl> 4, 4, 1, 1, 2,…
str(cars)
#> 'prt': 32 obs. of 11 variables in 1 partition:
#> $ mpg : num 21 21 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 ...
#> $ cyl : num 6 6 4 6 8 6 8 4 4 6 ...
#> $ disp: num 160 160 108 258 360 ...
#> $ hp : num 110 110 93 110 175 105 245 62 95 123 ...
#> $ drat: num 3.9 3.9 3.85 3.08 3.15 2.76 3.21 3.69 3.92 3.92 ...
#> $ wt : num 2.62 2.88 2.32 3.21 3.44 ...
#> $ qsec: num 16.5 17 18.6 19.4 17 ...
#> $ vs : num 0 0 1 1 0 1 0 1 1 1 ...
#> $ am : num 1 1 1 0 0 0 0 0 0 0 ...
#> $ gear: num 4 4 4 3 3 3 3 4 4 4 ...
#> $ carb: num 4 4 1 1 2 1 4 2 2 4 ...
str(cars, vec.len = 1)
#> 'prt': 32 obs. of 11 variables in 1 partition:
#> $ mpg : num 21 21 ...
#> $ cyl : num 6 6 ...
#> $ disp: num 160 160 ...
#> $ hp : num 110 110 ...
#> $ drat: num 3.9 3.9 ...
#> $ wt : num 2.62 ...
#> $ qsec: num 16.5 ...
#> $ vs : num 0 0 ...
#> $ am : num 1 1 ...
#> $ gear: num 4 4 ...
#> $ carb: num 4 4 ...
str(unclass(cars))
#> List of 1
#> $ :List of 4
#> ..$ meta :List of 7
#> .. ..$ path : chr "/tmp/Rtmpp89cNw/file157ea5cd09b/1.fst"
#> .. ..$ nrOfRows : num 32
#> .. ..$ keys : NULL
#> .. ..$ columnNames : chr [1:11] "mpg" "cyl" "disp" "hp" ...
#> .. ..$ columnBaseTypes: int [1:11] 5 5 5 5 5 5 5 5 5 5 ...
#> .. ..$ keyColIndex : NULL
#> .. ..$ columnTypes : int [1:11] 10 10 10 10 10 10 10 10 10 10 ...
#> .. ..- attr(*, "class")= chr "fstmetadata"
#> ..$ col_selection: NULL
#> ..$ row_selection: NULL
#> ..$ old_format : logi FALSE
str_sum(cars)
#> [1] "'prt':\t32 obs. of 11 variables in 1 partition:\n"