EVOLUTION-MANAGER
Edit File: corNatural.html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><title>R: General correlation in natural parameterization</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <link rel="stylesheet" type="text/css" href="R.css" /> </head><body> <table width="100%" summary="page for corNatural {nlme}"><tr><td>corNatural {nlme}</td><td style="text-align: right;">R Documentation</td></tr></table> <h2>General correlation in natural parameterization</h2> <h3>Description</h3> <p>This function is a constructor for the <code>corNatural</code> class, representing a general correlation structure in the “natural” parameterization, which is described under <code><a href="pdNatural.html">pdNatural</a></code>. Objects created using this constructor must later be initialized using the appropriate <code>Initialize</code> method. </p> <h3>Usage</h3> <pre> corNatural(value, form, fixed) </pre> <h3>Arguments</h3> <table summary="R argblock"> <tr valign="top"><td><code>value</code></td> <td> <p>an optional vector with the parameter values. Default is <code>numeric(0)</code>, which results in a vector of zeros of appropriate dimension being assigned to the parameters when <code>object</code> is initialized (corresponding to an identity correlation structure).</p> </td></tr> <tr valign="top"><td><code>form</code></td> <td> <p>a one sided formula of the form <code>~ t</code>, or <code>~ t | g</code>, specifying a time covariate <code>t</code> and, optionally, a grouping factor <code>g</code>. A covariate for this correlation structure must be integer valued. When a grouping factor is present in <code>form</code>, the correlation structure is assumed to apply only to observations within the same grouping level; observations with different grouping levels are assumed to be uncorrelated. Defaults to <code>~ 1</code>, which corresponds to using the order of the observations in the data as a covariate, and no groups.</p> </td></tr> <tr valign="top"><td><code>fixed</code></td> <td> <p>an optional logical value indicating whether the coefficients should be allowed to vary in the optimization, or kept fixed at their initial value. Defaults to <code>FALSE</code>, in which case the coefficients are allowed to vary.</p> </td></tr> </table> <h3>Value</h3> <p>an object of class <code>corNatural</code> representing a general correlation structure. </p> <h3>Author(s)</h3> <p>José Pinheiro and Douglas Bates <a href="mailto:bates@stat.wisc.edu">bates@stat.wisc.edu</a></p> <h3>See Also</h3> <p><code><a href="Initialize.corStruct.html">Initialize.corNatural</a></code>, <code><a href="pdNatural.html">pdNatural</a></code>, <code><a href="summary.corStruct.html">summary.corNatural</a></code> </p> <h3>Examples</h3> <pre> ## covariate is observation order and grouping factor is Subject cs1 <- corNatural(form = ~ 1 | Subject) </pre> <hr /><div style="text-align: center;">[Package <em>nlme</em> version 3.1-139 <a href="00Index.html">Index</a>]</div> </body></html>