fit_cox

Function that fits Cox proportional hazards models

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

fit_cox function

<dl><dt>x</dt>
<dd>a matrix of predictors excluding intercept with nobs observations.</dd>
<dt>y</dt>
<dd>a <code>Surv</code> object.</dd>
<dt>strata, control, rownames, nocenter</dt>
<dd>passed to <code><a href="/link/survival%3A%3Acoxph.fit()?package=mfp2&version=1.0.0" data-mini-rdoc="mfp2::survival::coxph.fit()">survival::coxph.fit()</a></code>.</dd>
<dt>weights</dt>
<dd>a numeric vector of length nobs of 'prior weights' to be used
in the fitting process.</dd>
<dt>offset</dt>
<dd>a numeric vector of length nobs of of a priori known component
to be included in the linear predictor during fitting.</dd>
<dt>method</dt>
<dd>a character string specifying the method for tie handling.
See <code><a href="/link/survival%3A%3Acoxph()?package=mfp2&version=1.0.0" data-mini-rdoc="mfp2::survival::coxph()">survival::coxph()</a></code>.</dd>
<dt>fast</dt>
<dd>a logical which determines how the model is fitted. The default
<code>TRUE</code> uses fast fitting routines (i.e. <code><a href="/link/survival%3A%3Acoxph.fit()?package=mfp2&version=1.0.0" data-mini-rdoc="mfp2::survival::coxph.fit()">survival::coxph.fit()</a></code>), while
<code>FALSE</code>uses the normal fitting routines (<code><a href="/link/survival%3A%3Acoxph()?package=mfp2&version=1.0.0" data-mini-rdoc="mfp2::survival::coxph()">survival::coxph()</a></code>) (used for
the final output of <code>mfp2</code>).</dd></dl>

Arguments

Function that fits Cox proportional hazards models — fit_cox

<dl>

<dt>x</dt>
<dd>a matrix of predictors excluding intercept with nobs observations.</dd>


<dt>y</dt>
<dd>a <code>Surv</code> object.</dd>


<dt>strata, control, rownames, nocenter</dt>
<dd>passed to <code><a href='https://rdrr.io/pkg/survival/man/agreg.fit.html'>survival::coxph.fit()</a></code>.</dd>


<dt>weights</dt>
<dd>a numeric vector of length nobs of 'prior weights' to be used
in the fitting process.</dd>


<dt>offset</dt>
<dd>a numeric vector of length nobs of of a priori known component
to be included in the linear predictor during fitting.</dd>


<dt>method</dt>
<dd>a character string specifying the method for tie handling.
See <code><a href='https://rdrr.io/pkg/survival/man/coxph.html'>survival::coxph()</a></code>.</dd>


<dt>fast</dt>
<dd>a logical which determines how the model is fitted. The default
<code>TRUE</code> uses fast fitting routines (i.e. <code><a href='https://rdrr.io/pkg/survival/man/agreg.fit.html'>survival::coxph.fit()</a></code>), while
<code>FALSE</code>uses the normal fitting routines (<code><a href='https://rdrr.io/pkg/survival/man/coxph.html'>survival::coxph()</a></code>) (used for
the final output of <code>mfp2</code>).</dd>

</dl>

fit_cox: Function that fits Cox proportional hazards models

Description

Usage

Value

Arguments