which.q {surveydata}

Identifies the columns indices corresponding to a specific question.

Description

In many survey systems, sub-questions take the form "Q1_a", "Q1_b", with the main question and sub-question separated by an underscore. This function conveniently returns column index of matches found for a question id in a surveydata object. It does this by using the pattern attribute of the surveydata object.

Usage

which.q(x, Q, ptn = pattern(x))

Arguments

x

Object to coerce to surveydata

Q

Character string with question number, e.g. "Q2"

ptn

A list with two elements, sep and exclude. See pattern() and which.q() for more detail.

See Also

questions() to return all questions matching the pattern()

Other Question functions: question_text_common(), question_text_unique(), question_text(), questions(), split_common_unique()

Examples

# Basic operations on a surveydata object, illustrated with the example dataset membersurvey

class(membersurvey)

questions(membersurvey)

which.q(membersurvey, "Q1")
which.q(membersurvey, "Q3")
which.q(membersurvey, c("Q1", "Q3"))

question_text(membersurvey, "Q3")
question_text_unique(membersurvey, "Q3")
question_text_common(membersurvey, "Q3")

# Extracting columns from a surveydata object

head(membersurvey[, "Q1"])
head(membersurvey["Q1"])
head(membersurvey[, "Q3"])
head(membersurvey[, c("Q1", "Q3")])

# Note that the result is always a surveydata object, even if only one column is extracted

head(membersurvey[, "id"])
str(membersurvey[, "id"])