.warn_if_onelevel

Factors with only one level happen if a character vector is converted to a
factor using <code><a href="/link/factor()?package=contrastable&version=1.0.2" data-mini-rdoc="contrastable::factor()">factor()</a></code> but without specifying anything for the <code>levels</code>
parameter. If you try to access or set the contrasts for a one-level factor,
you'll get an error that contrasts are undefined because you have 0 degrees
of freedom.

internal

Quickly set and summarize contrasts for factors prior to regression analyses. Intended comparisons, baseline conditions, and intercepts can be explicitly set and documented without the user needing to directly manipulate matrices. Reviews and introductions for contrast coding are available in Brehm and Alday (2022)<doi:10.1016/j.jml.2022.104334> and Schad et al. (2020)<doi:10.1016/j.jml.2019.104038>.

Thomas Sostarics

contrastable

Consistent Contrast Coding for Factors

.warn_if_onelevel function

<dl><dt>one_level_factors</dt>
<dd>Character vector of which factors are one level</dd>
<dt>model_data</dt>
<dd>Model data to look for factor columns</dd>
<dt>attempting_factors</dt>
<dd>Factor column names to check</dd></dl>

Arguments

Factors with only one level happen if a character vector is converted to a
factor using <code><a href='https://rdrr.io/r/base/factor.html'>factor()</a></code> but without specifying anything for the <code>levels</code>
parameter. If you try to access or set the contrasts for a one-level factor,
you'll get an error that contrasts are undefined because you have 0 degrees
of freedom.

Warn if one level factor — .warn_if_onelevel

<dl>

<dt>one_level_factors</dt>
<dd>Character vector of which factors are one level</dd>


<dt>model_data</dt>
<dd>Model data to look for factor columns</dd>


<dt>attempting_factors</dt>
<dd>Factor column names to check</dd>

</dl>

.warn_if_onelevel: Warn if one level factor

Description

Usage

Value

Arguments