15.1 Creating a Data Frame

15.1.1 Problem

You want to create a data frame from vectors.

15.1.2 Solution

You can put vectors together in a data frame with data.frame():

# Two starting vectors
g <- c("A", "B", "C")
x <- 1:3
dat <- data.frame(g, x)
dat
#>   g x
#> 1 A 1
#> 2 B 2
#> 3 C 3

15.1.3 Discussion

A data frame is essentially a list of vectors and factors. Each vector or factor can be thought of as a column in the data frame.

If your vectors are in a list, you can convert the list to a data frame with the as.data.frame() function:

lst <- list(group = g, value = x)    # A list of vectors

dat <- as.data.frame(lst)

The tidyverse way of creating a data frame is to use data_frame() or as_data_frame() (note the underscores instead of periods). This returns a special kind of data frame – a tibble – which behaves like a regular data frame in most contexts, but prints out more nicely and is specifically designed to play well with the tidyverse functions.

data_frame(g, x)
#> Warning: `data_frame()` was deprecated in tibble 1.1.0.
#> ℹ Please use `tibble()` instead.
#> This warning is displayed once every 8 hours.
#> Call `lifecycle::last_lifecycle_warnings()` to see where this warning was
#> generated.
#> # A tibble: 3 × 2
#>   g         x
#>   <chr> <int>
#> 1 A         1
#> 2 B         2
#> 3 C         3

# Convert the list of vectors to a tibble
as_data_frame(lst)

A regular data frame can be converted to a tibble using as_tibble():

as_tibble(dat)
#> # A tibble: 3 × 2
#>   group value
#>   <chr> <int>
#> 1 A         1
#> 2 B         2
#> 3 C         3