datawizard (version 0.13.0)

data_seek: Find variables by their names, variable or value labels

Description

This functions seeks variables in a data frame, based on patterns that either match the variable name (column name), variable labels, value labels or factor levels. Matching variable and value labels only works for "labelled" data, i.e. when the variables either have a label attribute or labels attribute.

data_seek() is particular useful for larger data frames with labelled data - finding the correct variable name can be a challenge. This function helps to find the required variables, when only certain patterns of variable names or labels are known.

Usage

data_seek(data, pattern, seek = c("names", "labels"), fuzzy = FALSE)

Value

A data frame with three columns: the column index, the column name and - if available - the variable label of all matched variables in data.

Arguments

data

A data frame.

pattern

Character string (regular expression) to be matched in data. May also be a character vector of length > 1. pattern is searched for in column names, variable label and value labels attributes, or factor levels of variables in data.

seek

Character vector, indicating where pattern is sought. Use one or more of the following options:

• "names": Searches in column names. "column_names" and "columns" are aliases for "names".

• "labels": Searches in variable labels. Only applies when a label attribute is set for a variable.

• "values": Searches in value labels or factor levels. Only applies when a labels attribute is set for a variable, or if a variable is a factor. "levels" is an alias for "values".

• "all": Searches in all of the above.

fuzzy

Logical. If TRUE, "fuzzy matching" (partial and close distance matching) will be used to find pattern.

Examples

# seek variables with "Length" in variable name or labels
data_seek(iris, "Length")

# seek variables with "dependency" in names or labels
# column "e42dep" has a label-attribute "elder's dependency"
data(efc)
data_seek(efc, "dependency")

# "female" only appears as value label attribute - default search is in
# variable names and labels only, so no match
data_seek(efc, "female")
# when we seek in all sources, we find the variable "e16sex"
data_seek(efc, "female", seek = "all")

# typo, no match
data_seek(iris, "Lenght")
# typo, fuzzy match
data_seek(iris, "Lenght", fuzzy = TRUE)