<dd><p>Vector of integers specifying each SNP's chromosome.<br>
Typically <code>&lt;bigSNP&gt;$map$chromosome</code>.</p></dd>


<dt>FUN</dt>
<dd><p>The function to be applied. It must take a
<a href="https://privefl.github.io/bigstatsr/reference/FBM.code256-class.html" class="external-link">FBM.code256</a> as first argument and <code>ind.chr</code>,
an another argument to provide subsetting over SNPs.
You can access the number of the chromosome by using <code>attr(ind.chr, "chr")</code>.</p></dd>


<dt>com