title: Extract coefficient functions from a fitted pfr-object from refund R package
body: <p>I am trying to extract coefficients from a fitted <code>pfr</code>-object. </p>
  
  <ul>
  <li><p>I fit Functional Generalized Linear Model (FGLM) of the form: </p>
  
  <p><code>E[Y_i] = X_i' \beta + \int_T f[t, Z_i(t)] dt</code>, </p></li>
  <li><p>I then try to extract coefficients via <code>coef(fit_FGAM, n = c(n_1,n_2))</code>, where <code>fit_FGAM</code> is a fitted model object. </p></li>
  <li><p>From the documentation, I read: <em><code>n</code> - integer vector indicating the number of equally spaced coordinates for each argument. If length 1, the same number is used for each argument. Otherwise, the length must match <code>object$smooth[[select]]$dim</code>.</em></p></li>
  </ul>
  
  <p>It is left unclear to me: </p>
  
  <ol>
  <li><p>Which element of, say, 2-element vector <code>n = c(n_1,n_2)</code>corresponds to argument <code>t</code>, and which to argument <code>Z_i</code>? </p></li>
  <li><p>I presume (guess) that by default, the <strong>range of coordinates</strong> for argument <code>t</code> (time) is <code>(min(t), min(t))</code>, given all <code>t</code> coordinates are the same for all observations - is this the case? </p></li>
  <li><p>How the range of coordinates <code>Z_i</code> is defined? Is it a range of <strong>all</strong> (scalar) values present in dataset within <code>Z_i</code> across all time points and all observations? </p></li>
  </ol>