Convert a data frame to a user-defined format

Source: R/fmt.R

This function takes a data frame as input and converts it to a user-defined format based on the information contained in the data frame. The data frame should have 5 columns: "Name", "Type", "Expression", "Label" and "Order".

# S3 method for data.frame
as.fmt(x)

Arguments

x

The data frame to convert.

Value

A format catalog based on the information contained in the input data frame.

Details

The as.fmt.data.frame function converts a data frame to a user-defined format.

To understand the structure of the input data frame, create a user-defined format and use the as.data.frame method to convert the format to a data frame. Then observe the columns and organization of the data.

Input Data Frame Specifications

The input data frame should contain the following columns:

  • Name: The name of the format

  • Type: The type of format. See the type codes below.

  • Expression: The formatting expression. The expression will hold different types of values depending on the format type. Within the data frame, this expression is stored as a character string.

  • Label: The label for user-defined, "U" type formats.

  • Order: The order for user-defined, "U" type formats.

  • Factor: An optional column for "U" type formats that sets the "as.factor" parameter. Valid values are TRUE, FALSE, or NA.

Any additional columns will be ignored. Column names are case-insensitive.

Valid values for the "Type" column are as follows:

  • U: User Defined List created with the value function.

  • S: A formatting string of formatting codes. See FormattingStrings.

  • F: A vectorized function.

  • V: A named vector lookup.

The "Label", "Order", and "Factor" columns are used only for a type "U", user-defined format created with the value function.

See also

Other fmt: as.data.frame.fmt(), as.fmt(), condition(), is.format(), labels.fmt(), print.fmt(), value()

Examples

# Create a user-defined format 
f1 <- value(condition(x == "A", "Label A"),
            condition(x == "B", "Label B"),
            condition(TRUE, "Other"))
           
# Convert user-defined format to data frame to view the structure
df <- as.data.frame(f1)
print(df)

# Name Type Expression   Label Order Factor
# 1 f1    U   x == "A" Label A    NA  FALSE
# 2 f1    U   x == "B" Label B    NA  FALSE
# 3 f1    U       TRUE   Other    NA  FALSE

# Convert data frame back to a user-defined format 
f2 <- as.fmt(df)

# Use re-converted format
fapply(c("A", "B", "C", "B"), f2)
# [1] "Label A" "Label B" "Other"   "Label B"