v: Returns a list of column names from the data dictionary for...

In bokov/tidbits: Various small utilities for simplifying data preparation and analysis

Returns a list of column names from the data dictionary for which the column named in the first argument is true. The first arg can be either a string or a name. The second must be a data.frame

Description

Returns a list of column names from the data dictionary for which the column named in the first argument is true. The first arg can be either a string or a name. The second must be a data.frame

Usage

v(
  var,
  dat,
  retcol = getOption("tb.retcol", "column"),
  dictionary = get("dct0"),
  asname = F
)

Arguments

var	Either a string or a name, of a column in 'dictionary'
dat	An optional data.frame, to constrain which rows of the 'dictionary' object get used
retcol	Which column to return– by default the same as used for 'matchcol'
dictionary	A 'data.frame' that is used as a data dictionary. It must at minimum contain a column of column-names for the dataset for which it is a data dictionary ('matchcol') and one or more columns each representing a _group_ of columns in the dataset, such that a TRUE or T value means the column whose name is the value of 'matchcol' is the name of a column in the data that belongs to the group defined by the grouping column. These grouping columns are what the argument 'var' is supposed to refer to. We will use the convention that grouping column names begin with 'c_' but this convention is not (currently) enforced programmatically.

Examples

dct0 <- tblinfo(mtcars);

v();

# Numeric variables in mtcars that behave like discrete variables
v(c_ordinal);
# Numeric variables in mtcars
v(c_numeric);
# Variables in mtcars that only have two values, so could be encoded as
# boolean
v(c_tf);

# Non-default data dictionary
dct1 <- tblinfo(state.x77)
v(c_ordinal,dict=dct1)
v(c_factor,dict=dct1)
v(c_tf,dict=dct1)
v(c_numeric,dict=dct1)

bokov/tidbits documentation built on Jan. 26, 2024, 6:25 p.m.