es. Remember that
<code>maxp</code> cannot be smaller than the number of observations
(rows in <code>X</code>), by default it is 1e6.</p>
<p>In the code below we assume that you have a big matrix in a file
<em>X.txt</em>. Reading such matrix can be slow, but if you set
<code>backingfile</code> and <code>descriptorfile</code> you have to do
that once and next time you can use <code>attach.big.matrix</code> which
is much faster.</p>
<div class="sourceCode" id="cb9"><pre class="sourceCode r"><code class="sourc