(cal_time)6  </span>
<span class="r-out co"><span class="r-pr">#&gt;</span>                                                        3.543e+01  </span>
<span class="r-out co"><span class="r-pr">#&gt;</span>  poly(j, degree = poly_degree, raw = TRUE)2:as.factor(cal_time)6  </span>
<span class="r-out co"><span class="r-pr">#&gt;</span>                                                       -2.821e-01  </span>
<span class="r-out co"><span class="r-pr">#&gt;</span>  poly(j, degree = poly_degree, raw = TRUE)3:a