📄 logtrans.html
字号:
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html><head><title>R: Estimate log Transformation Parameter</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<link rel="stylesheet" type="text/css" href="../../R.css">
</head><body>
<table width="100%" summary="page for logtrans {MASS}"><tr><td>logtrans {MASS}</td><td align="right">R Documentation</td></tr></table>
<h2>Estimate log Transformation Parameter</h2>
<h3>Description</h3>
<p>
Find and optionally plot the marginal (profile) likelihood for alpha
for a transformation model of the form <code>log(y + alpha) ~ x1 + x2 + ...</code>.
</p>
<h3>Usage</h3>
<pre>
logtrans(object, ...)
## Default S3 method:
logtrans(object, ..., alpha = seq(0.5, 6, by = 0.25) - min(y),
plotit = TRUE, interp =, xlab = "alpha",
ylab = "log Likelihood")
## S3 method for class 'formula':
logtrans(object, data, ...)
## S3 method for class 'lm':
logtrans(object, ...)
</pre>
<h3>Arguments</h3>
<table summary="R argblock">
<tr valign="top"><td><code>object</code></td>
<td>
Fitted linear model object, or formula defining the untransformed
model that is <code>y ~ x1 + x2 + ...</code>. The function is generic.
</td></tr>
<tr valign="top"><td><code>...</code></td>
<td>
If <code>object</code> is a formula, this argument may specify a data frame
as for <code>lm</code>.
</td></tr>
<tr valign="top"><td><code>alpha</code></td>
<td>
Set of values for the transformation parameter, alpha.
</td></tr>
<tr valign="top"><td><code>plotit</code></td>
<td>
Should plotting be done?
</td></tr>
<tr valign="top"><td><code>interp</code></td>
<td>
Should the marginal log-likelihood be interpolated with a spline
approximation? (Default is <code>TRUE</code> if plotting is to be done and
the number of real points is less than 100.)
</td></tr>
<tr valign="top"><td><code>xlab</code></td>
<td>
as for <code>plot</code>.
</td></tr>
<tr valign="top"><td><code>ylab</code></td>
<td>
as for <code>plot</code>.
</td></tr>
<tr valign="top"><td><code>data</code></td>
<td>
optional <code>data</code> argument for <code>lm</code> fit.
</td></tr>
</table>
<h3>Value</h3>
<p>
List with components <code>x</code> (for alpha) and <code>y</code> (for the marginal
log-likelihood values).</p>
<h3>Side Effects</h3>
<p>
A plot of the marginal log-likelihood is produced, if requested,
together with an approximate mle and 95% confidence interval.
</p>
<h3>References</h3>
<p>
Venables, W. N. and Ripley, B. D. (2002)
<EM>Modern Applied Statistics with S.</EM> Fourth edition. Springer.
</p>
<h3>See Also</h3>
<p>
<code><a href="boxcox.html">boxcox</a></code>
</p>
<h3>Examples</h3>
<pre>
logtrans(Days ~ Age*Sex*Eth*Lrn, data = quine,
alpha = seq(0.75, 6.5, len=20))
</pre>
<hr><div align="center">[Package <em>MASS</em> version 7.2-44 <a href="00Index.html">Index]</a></div>
</body></html>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -