DDIwR (version 0.9)

getMetadata: Extract metadata information

Description

Extract a list containing the variable labels, value labels and any available information about missing values.

Usage

getMetadata(x, save = FALSE, OS = "Windows", ...)

Arguments

x

A path to a file, or a data frame object

save

Boolean, save an .R file in the same directory

OS

The target operating system, for the eol - end of line separator, if saving the file

...

Additional arguments for this function (internal uses only)

Value

A list containing all variables, their corresponding variable labels and value labels, and (if applicable) missing values if imported and found.

Details

This function reads an XML file containing a DDI codebook version 2.5, or an SPSS or Stata file and returns a list containing the variable labels, value labels, plus some other useful information.

It additionally attempts to automatically detect a type for each variable:

cat:	categorical using numeric values
catchar:	categorical using character values
num:	numerical
numcat:	numerical variable with very few values (ex. number of children)

By default, this function extracts the metadata into an R list object, but when the argument save is activated, the argument OS (case insensitive) can be either: "Windows" (default), or "Win", "MacOS", "Darwin", "Apple", "Mac", "Linux".

The end of line separator changes only when the target OS is different from the running OS.

For the moment, only DDI version 2.5 (Codebook) is supported, but DDI Lifecycle is planned to be implemented.

Examples

# NOT RUN {
x <- data.frame(
    A = declared(
        c(1:5, -92),
        labels = c(Good = 1, Bad = 5, NR = -92),
        na_values = -92
    ),
    C = declared(
        c(1, -91, 3:5, -92),
        labels = c(DK = -91, NR = -92),
        na_values = c(-91, -92)
    )
)

getMetadata(x)$dataDscr

# }