ariable indicating
which is the functional observation in each row.</p></dd>


<dt>variables</dt>
<dd><p>A vector of characters of the column names
of the data frame <code>dt</code>
indicating the functional variables.</p></dd>


<dt>n_basis</dt>
<dd><p>An integer variable specifying the number of basis functions;
default value is 30.
See details on basis functions.</p></dd>


<dt>n_order</dt>
<dd><p>An integer specifying the order of b-splines,
which is one higher than their degree.
The default of 4 gives 