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<table width="100%" summary="page for OvaryCancer"><tr><td>OvaryCancer</td><td align="right">R Documentation</td></tr></table>

<h2>Ovary Cancer Data</h2>

<h3>Description</h3>


<p>Data from Obel (1975) about a retrospective study of ovary cancer
carried out in 1973.  Information was obtained from 299 women, who
were operated for ovary cancer 10 years before.
</p>


<h3>Usage</h3>

<pre>
data("OvaryCancer")
</pre>


<h3>Format</h3>


<p>A data frame with 16 observations and 5 variables.
</p>

<dl>
<dt>Freq</dt><dd><p>frequency.</p>
</dd>
<dt>stage</dt><dd><p>factor indicating the stage of the cancer at the
time of operation (early, advanced).</p>
</dd>
<dt>operation</dt><dd><p>factor indicating type of operation (radical,
limited).</p>
</dd>
<dt>survival</dt><dd><p>factor indicating survival status after 10 years
(yes, no).</p>
</dd>
<dt>xray</dt><dd><p>factor indicating whether X-ray treatment was received
(yes, no).</p>
</dd>
</dl>



<h3>Source</h3>


<p>E. B. Andersen (1991),
The Statistical Analysis of Categorical Data, Table 6.4.
</p>


<h3>References</h3>


<p>E. B. Obel (1975),
A Comparative Study of Patients with Cancer of the Ovary Who Have
Survived More or Less Than 10 Years.
<EM>Acta Obstetricia et Gynecologica Scandinavica</EM>, 
<B>55</B>, 429-439.
</p>
<p>E. B. Andersen (1991),
<EM>The Statistical Analysis of Categorical Data</EM>.
2nd edition.
Springer-Verlag, Berlin.
</p>


<h3>Examples</h3>

<pre>
data("OvaryCancer")
tab &lt;- xtabs(Freq ~ xray + survival + stage + operation, data = OvaryCancer)
ftable(tab, col.vars = "survival", row.vars = c("stage", "operation", "xray"))

## model: ~ xray * operation * stage + survival * stage
## interpretation: treat xray, operation, stage as fixed margins,
##   the survival depends on stage, but not xray and operation.
doubledecker(survival ~ stage + operation + xray, data = tab)
mosaic(~ stage + operation + xray + survival,
  split = c(FALSE, TRUE, TRUE, FALSE), data = tab, keep = FALSE,
  gp = gpar(fill = rev(grey.colors(2))))
mosaic(~ stage + operation + xray + survival,
  split = c(FALSE, TRUE, TRUE, FALSE), data = tab, keep = FALSE,
  expected = ~ xray * operation * stage + survival*stage)
</pre>


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