>part_size</code> to set a good value.</p></dd>


<dt>.transform</dt>
<dd><p>Function to transform each data frame corresponding to each
block of selected columns. Default doesn't change anything.</p></dd>


<dt>.combine</dt>
<dd><p>Function to combine results (list of data frames).</p></dd>


<dt>skip</dt>
<dd><p>Number of lines to skip at the beginning of <code>file</code>.</p></dd>


<dt>select</dt>
<dd><p>Indices of columns to keep (sorted). Default keeps them all.</p></dd>


<dt>progress</dt>
<dd><p>Sh