Format Data Function

2021-07-24

How to use fdata()

Data can be formatted by assigning formats to the format attribute of the columns in your dataframe or tibble, and then by calling the fdata() function on that data. A sample program is as follows:

# Set up data frame
df <- mtcars[1:10, c("mpg", "cyl")]
df

# Define and assign formats
attr(df$mpg, "format") <- value(condition(x >= 20, "High"),
                                condition(x < 20, "Low"))

attr(df$cyl, "format") <- function(x) format(x, nsmall = 1)

# Apply formatting
fdata(df)

Here is the mtcars subset before formatting:

#                    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
# Valiant           18.1   6
# Duster 360        14.3   8
# Merc 240D         24.4   4
# Merc 230          22.8   4
# Merc 280          19.2   6

And here is the mtcars subset after formatting:

#                    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
# Valiant           Low  6.0
# Duster 360        Low  8.0
# Merc 240D         High 4.0
# Merc 230          High 4.0
# Merc 280          Low  6.0

You may apply formatting to variables of any data type: character, numeric, date, etc. Internally, the fdata() function is using the fapply() function on each column in the data frame. If there is no format assigned to a column, that column is returned unaltered.

Next: Format Apply Function