center_matrix

Multivariable fractional polynomial algorithm simultaneously selects variables and functional forms in both generalized linear models and Cox proportional hazard models. Key references for this algorithm are Royston and Altman (1994)<doi:10.2307/2986270> and Sauerbrei and Royston (2008, ISBN:978-0-470-02842-1). In addition, it can model a 'sigmoid' relationship between variable x and an outcome variable y using the approximate cumulative distribution transformation proposed by Royston (2014) <doi:10.1177/1536867X1401400206>. This feature distinguishes it from a standard fractional polynomial function, which lacks the ability to achieve such modeling.

Edwin Kipruto

mfp2

Multivariable Fractional Polynomial Models with Extensions

Michael Kammer

Patrick Royston

Willi Sauerbrei

center_matrix function

<dl><dt>mat</dt>
<dd>a transformed data matrix.</dd>
<dt>centers</dt>
<dd>a vector of centering values. Length must be equal to the
number of columns in <code>mat</code>. If <code>NULL</code> (default) then
centering values are determined by the function (see Details).</dd></dl>

Arguments

Simple function to center data — center_matrix

<dl>

<dt>mat</dt>
<dd>a transformed data matrix.</dd>


<dt>centers</dt>
<dd>a vector of centering values. Length must be equal to the
number of columns in <code>mat</code>. If <code>NULL</code> (default) then
centering values are determined by the function (see Details).</dd>

</dl>

center_matrix: Simple function to center data

Description

Usage

Value

Arguments

Details

Examples