length_by

<code>length_by</code> computes the the length of a (atomic) vector by group. The
argument <code>na.rm</code> can be used to include (FALSE) or exclude (TRUE)
missing values.

Offers a suite of functions to prepare questionnaire data for analysis (perhaps other types of data as well). By data preparation, I mean data analytic tasks to get your raw data ready for statistical modeling (e.g., regression). There are functions to investigate missing data, reshape data, validate responses, recode variables, score questionnaires, center variables, aggregate by groups, shift scores (i.e., leads or lags), etc. It provides functions for both single level and multilevel (i.e., grouped) data. With a few exceptions (e.g., ncases()), functions without an "s" at the end of their primary word (e.g., center_by()) act on atomic vectors, while functions with an "s" at the end of their primary word (e.g., centers_by()) act on multiple columns of a data.frame.

David Disabato

quest

Prepare Questionnaire Data for Analysis

length_by function

<dl><dt>x</dt>
<dd>atomic vector.</dd>
<dt>grp</dt>
<dd>atomic vector or list of atomic vectors (e.g., data.frame)
specifying the groups. The atomic vector(s) must be the length of x or else
an error is returned.</dd>
<dt>na.rm</dt>
<dd>logical vector of length 1 specifying whether to include (FALSE)
or exclude (TRUE) missing values.</dd>
<dt>sep</dt>
<dd>character vector of length 1 specifying what string should
separate different group values when naming the return object. This
argument is only used if grp is a list of atomic vectors (e.g.,
data.frame).</dd></dl>

Arguments

Length of a (Atomic) Vector by Group — length_by

<dl>

<dt>x</dt>
<dd>atomic vector.</dd>


<dt>grp</dt>
<dd>atomic vector or list of atomic vectors (e.g., data.frame)
specifying the groups. The atomic vector(s) must be the length of x or else
an error is returned.</dd>


<dt>na.rm</dt>
<dd>logical vector of length 1 specifying whether to include (FALSE)
or exclude (TRUE) missing values.</dd>


<dt>sep</dt>
<dd>character vector of length 1 specifying what string should
separate different group values when naming the return object. This
argument is only used if grp is a list of atomic vectors (e.g.,
data.frame).</dd>

</dl>

length_by: Length of a (Atomic) Vector by Group

Description

Usage

Value

Arguments

See Also

Examples