The formats function extracts all assigned formats from a
data frame, and returns them in a named list. The function also
assigns formats from a named list.
formats(x)
formats(x) <- valueA named list of formats.
If formats are assigned to the "format" attributes of the data frame
columns, the formats function will extract those formats. The
function will return the formats in a named list, where the names
correspond to the name of the column that the format was assigned to.
If a column does not have a format attribute assigned, that column
will not be included in the list.
When used on the receiving side of an assignment, the function will assign formats to a data frame. The formats should be in a named list, where each name corresponds to the data frame column to assign the format to.
The formats function can also accept a format catalog as input.
This feature allows you to save formats in metadata, load them into a
format catalog, and quickly assign them to a data frame or tibble. See
the fcat function for additional information.
Finally, if you wish to clear out format attributes, assign a NULL
value to the formats function.
fdata to display formatted data,
value to create user-defined formats,
fapply to apply formats to a vector, and
fcat to create a format catalog. Also see
FormattingStrings for documentation on formatting strings.
# Take subset of data
df1 <- mtcars[1:5, c("mpg", "cyl") ]
# Print current state
print(df1)
#> mpg cyl
#> Mazda RX4 21.0 6
#> Mazda RX4 Wag 21.0 6
#> Datsun 710 22.8 4
#> Hornet 4 Drive 21.4 6
#> Hornet Sportabout 18.7 8
# mpg cyl
# Mazda RX4 21.0 6
# Mazda RX4 Wag 21.0 6
# Datsun 710 22.8 4
# Hornet 4 Drive 21.4 6
# Hornet Sportabout 18.7 8
# Assign formats
attr(df1$mpg, "format") <- value(condition(x >= 20, "High"),
condition(x < 20, "Low"))
#> # A user-defined format: 2 conditions
#> Name Type Expression Label Order
#> 1 x U x >= 20 High NA
#> 2 x U x < 20 Low NA
attr(df1$cyl, "format") <- function(x) format(x, nsmall = 1)
# Display formatted data
fdata(df1)
#> mpg cyl
#> Mazda RX4 High 6.0
#> Mazda RX4 Wag High 6.0
#> Datsun 710 High 4.0
#> Hornet 4 Drive High 6.0
#> Hornet Sportabout Low 8.0
# mpg cyl
# Mazda RX4 High 6.0
# Mazda RX4 Wag High 6.0
# Datsun 710 High 4.0
# Hornet 4 Drive High 6.0
# Hornet Sportabout Low 8.0
# Extract format list
lst <- formats(df1)
# Alter format list and reassign
lst$mpg <- value(condition(x >= 22, "High"),
condition(x < 22, "Low"))
#> # A user-defined format: 2 conditions
#> Name Type Expression Label Order
#> 1 x U x >= 22 High NA
#> 2 x U x < 22 Low NA
lst$cyl <- function(x) format(x, nsmall = 2)
formats(df1) <- lst
# Display formatted data
fdata(df1)
#> mpg cyl
#> Mazda RX4 Low 6.00
#> Mazda RX4 Wag Low 6.00
#> Datsun 710 High 4.00
#> Hornet 4 Drive Low 6.00
#> Hornet Sportabout Low 8.00
# mpg cyl
# Mazda RX4 Low 6.00
# Mazda RX4 Wag Low 6.00
# Datsun 710 High 4.00
# Hornet 4 Drive Low 6.00
# Hornet Sportabout Low 8.00
# Clear formats
formats(df1) <- NULL
# Confirm formats are cleared
formats(df1)
#> list()
# list()