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

<h2>Helicopter Data</h2>

<h3>Description</h3>


<p>The <code>helicopter</code> data frame has 9 rows and 6 columns.
</p>
<p>Experimental design for studying the influences of the factors wing 
length and wing width on a paper helicopter's flight time.  The goal is 
to find the factor setting that maximizes flight time when the paper 
helicopter is dropped from a fixed height of 15.5 feet
</p>


<h3>Usage</h3>

<pre>data(helicopter)</pre>


<h3>Format</h3>


<p>A data frame with 9 observations on the following 6 variables:
</p>

<dl>
<dt><code>L</code></dt><dd>
<p>wing length in inches;
</p>
</dd> 
<dt><code>W</code></dt><dd>
<p>wing width in inches;
</p>
</dd>
<dt><code>B</code></dt><dd>
<p>base length (always set to 3in);
</p>
</dd>
<dt><code>H</code></dt><dd>
<p>base height (always set to 2in);
</p>
</dd>
<dt><code>Order</code></dt><dd>
<p>run order;
</p>
</dd>
<dt><code>Time</code></dt><dd>
<p>flight time in seconds.</p>
</dd>
</dl>



<h3>Source</h3>


<p>The data were obtained from
</p>
<p>Annis, D. H. (2006)  Rethinking the paper helicopter: Combining 
statistical and engineering knowledge.  <EM>The American 
Statistician</EM>, <B>59</B>, 320&ndash;326. 
</p>


<h3>References</h3>


<p>Box, G. E. P. (1992)  Teaching engineers experimental design with a
paper helicopter.  <EM>Quality Engineering</EM>, <B>4</B>, 453&ndash;459.
</p>


<h3>Examples</h3>

<pre>
data(helicopter)
##
## fit model (5) of Annis (2005)
## -----------------------------
heli &lt;- helicopter
##
heli$LW &lt;- heli$L * heli$W
heli$S &lt;- heli$B * heli$H + ( 2 * heli$L + 1 ) * heli$W
heli$logTime &lt;- log( heli$Time )
heli$Y &lt;- heli$logTime + log( heli$S ) / 2
#
heli.nlreg &lt;- nlreg( Y ~ b0 + b1 * log( b2^2 / LW + LW ), data = heli, 
                    start = c( b0 = 6, b1 = -1, b2 = 20 ) )
</pre>


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