class="comment">%  idx: x(idx) maps to z</span>
0006 <span class="comment">%</span>
0007 <span class="comment">%  x: data matrix</span>
0008 <span class="comment">%  shifts: array of shifts to apply</span>
0009 <span class="comment">%  keep: number of components shifted regressor PCs to keep (default: all)</span>
0010 <span class="comment">%  threshold: discard PCs with eigenvalues below this (default: 0)</span>
0011 <span class="comment">%  w: ignore samples with absolute value above this</span>
0012 <span