We’re delighted to announce that haven 2.2.0 is now on CRAN. haven enables R to read and write various data formats used by other statistical packages by wrapping the ReadStat C library written by Evan Miller.
You can install haven from CRAN with:
install.packages("haven")
This release features big improvements thanks to the hard work of
Mikko Marttila: all read_*() functions gain three new arguments that allow you to read in only part of a large file. I’ll quickly show of these features by saving out the
diamonds dataset to a Stata file:
library(haven)
write_dta(ggplot2::diamonds, "diamonds.dta")
n_max and skip allow you to read in just a portion of the rows:
read_dta("diamonds.dta", n_max = 5)
#> # A tibble: 5 x 10
#> carat cut color clarity depth table price x y z
#> <dbl> <dbl+lbl> <dbl+lbl> <dbl+lbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 0.23 5 [Ideal] 2 [E] 2 [SI2] 61.5 55 326 3.95 3.98 2.43
#> 2 0.21 4 [Premium] 2 [E] 3 [SI1] 59.8 61 326 3.89 3.84 2.31
#> 3 0.23 2 [Good] 2 [E] 5 [VS1] 56.9 65 327 4.05 4.07 2.31
#> 4 0.290 4 [Premium] 6 [I] 4 [VS2] 62.4 58 334 4.2 4.23 2.63
#> 5 0.31 2 [Good] 7 [J] 2 [SI2] 63.3 58 335 4.34 4.35 2.75
read_dta("diamonds.dta", skip = 4, n_max = 5)
#> # A tibble: 5 x 10
#> carat cut color clarity depth table price x y z
#> <dbl> <dbl+lbl> <dbl+lbl> <dbl+lb> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 0.31 2 [Good] 7 [J] 2 [SI2] 63.3 58 335 4.34 4.35 2.75
#> 2 0.24 3 [Very Goo… 7 [J] 6 [VVS2] 62.8 57 336 3.94 3.96 2.48
#> 3 0.24 3 [Very Goo… 6 [I] 7 [VVS1] 62.3 57 336 3.95 3.98 2.47
#> 4 0.26 3 [Very Goo… 5 [H] 3 [SI1] 61.9 55 337 4.07 4.11 2.53
#> 5 0.22 1 [Fair] 2 [E] 4 [VS2] 65.1 61 337 3.87 3.78 2.49
And col_select() allows you to read in just some of the columns, using the same syntax that you use with
dplyr::select():
read_dta("diamonds.dta", col_select = c(x:z))
#> # A tibble: 53,940 x 3
#> x y z
#> <dbl> <dbl> <dbl>
#> 1 3.95 3.98 2.43
#> 2 3.89 3.84 2.31
#> 3 4.05 4.07 2.31
#> 4 4.2 4.23 2.63
#> 5 4.34 4.35 2.75
#> 6 3.94 3.96 2.48
#> 7 3.95 3.98 2.47
#> 8 4.07 4.11 2.53
#> 9 3.87 3.78 2.49
#> 10 4 4.05 2.39
#> # … with 53,930 more rows
read_dta("diamonds.dta", col_select = starts_with("c"))
#> # A tibble: 53,940 x 4
#> carat cut color clarity
#> <dbl> <dbl+lbl> <dbl+lbl> <dbl+lbl>
#> 1 0.23 5 [Ideal] 2 [E] 2 [SI2]
#> 2 0.21 4 [Premium] 2 [E] 3 [SI1]
#> 3 0.23 2 [Good] 2 [E] 5 [VS1]
#> 4 0.290 4 [Premium] 6 [I] 4 [VS2]
#> 5 0.31 2 [Good] 7 [J] 2 [SI2]
#> 6 0.24 3 [Very Good] 7 [J] 6 [VVS2]
#> 7 0.24 3 [Very Good] 6 [I] 7 [VVS1]
#> 8 0.26 3 [Very Good] 5 [H] 3 [SI1]
#> 9 0.22 1 [Fair] 2 [E] 4 [VS2]
#> 10 0.23 3 [Very Good] 5 [H] 5 [VS1]
#> # … with 53,930 more rows
These features allow you to read in datasets that would otherwise not fit in memory, and should substantially improve performance when you only need a few rows or columns from a large file.
This release includes a number of other bug fixes and small improvements, see the changelog for a complete list.
Acknowledgements
A big thanks to everyone who helped out with this release: @aaronrudkin, @batpigandme, @ccccfys, @courtiol, @hadley, @Hadsga, @jeremy17-Endo, @KyleHaynes, @lguangyu, @mihagazvoda, @mikmart, @MokeEire, @npaszty, @pvanheus, @RaymondBalise, @sclewis23, @shubham1637, @sigbertklinke, @steffen-stell, and @ttrodrigz.