tidyr 0.5.0
This article is originally published at https://www.rstudio.com/blog/
I’m pleased to announce tidyr 0.5.0. tidyr makes it easy to “tidy” your data, storing it in a consistent form so that it’s easy to manipulate, visualise and model. Tidy data has a simple convention: put variables in the columns and observations in the rows. You can learn more about it in the tidy data vignette. Install it with:
install.packages("tidyr")
This release has three useful new features:
separate_rows()separates values that contain multiple values separated by a delimited into multiple rows. Thanks to Aaron Wolen for the contribution!
df <- data_frame(x = 1:2, y = c("a,b", "d,e,f"))
df %>%
separate_rows(y, sep = ",")
#> Source: local data frame [5 x 2]
#>
#> x y
#> <int> <chr>
#> 1 1 a
#> 2 1 b
#> 3 2 d
#> 4 2 e
#> 5 2 f
Compare with separate() which separates into (named) columns:
df %>%
separate(y, c("y1", "y2", "y3"), sep = ",", fill = "right")
#> Source: local data frame [2 x 4]
#>
#> x y1 y2 y3
#> * <int> <chr> <chr> <chr>
#> 1 1 a b <NA>
#> 2 2 d e f
spread()gains asepargument. Setting this will name columns as “key|sep|value”. This is useful when you’re spreading based on a numeric column:
df <- data_frame(
x = c(1, 2, 1),
key = c(1, 1, 2),
val = c("a", "b", "c")
)
df %>% spread(key, val)
#> Source: local data frame [2 x 3]
#>
#> x 1 2
#> * <dbl> <chr> <chr>
#> 1 1 a c
#> 2 2 b <NA>
df %>% spread(key, val, sep = "_")
#> Source: local data frame [2 x 3]
#>
#> x key_1 key_2
#> * <dbl> <chr> <chr>
#> 1 1 a c
#> 2 2 b <NA>
unnest()gains a.separgument. This is useful if you have multiple columns of data frames that have the same variable names:
df <- data_frame(
x = 1:2,
y1 = list(
data_frame(y = 1),
data_frame(y = 2)
),
y2 = list(
data_frame(y = "a"),
data_frame(y = "b")
)
)
df %>% unnest()
#> Source: local data frame [2 x 3]
#>
#> x y y
#> <int> <dbl> <chr>
#> 1 1 1 a
#> 2 2 2 b
df %>% unnest(.sep = "_")
#> Source: local data frame [2 x 3]
#>
#> x y1_y y2_y
#> <int> <dbl> <chr>
#> 1 1 1 a
#> 2 2 2 b
It also gains a .id column that makes the names of the list explicit:
df <- data_frame(
x = 1:2,
y = list(
a = 1:3,
b = 3:1
)
)
df %>% unnest()
#> Source: local data frame [6 x 2]
#>
#> x y
#> <int> <int>
#> 1 1 1
#> 2 1 2
#> 3 1 3
#> 4 2 3
#> 5 2 2
#> 6 2 1
df %>% unnest(.id = "id")
#> Source: local data frame [6 x 3]
#>
#> x y id
#> <int> <int> <chr>
#> 1 1 1 a
#> 2 1 2 a
#> 3 1 3 a
#> 4 2 3 b
#> 5 2 2 b
#> 6 2 1 b
tidyr 0.5.0 also includes a bumper crop of bug fixes, including fixes for spread() and gather() in the presence of list-columns. Please see the release notes for a complete list of changes.
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This article is originally published at https://www.rstudio.com/blog/
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