// we should really really do a binary search rather than iterate
for (Points::size_type idx = 0; idx < c.n_samples - 1; ++idx) {
left = idx;
window_space = item_to_window (Duple (c.samples[idx].x, 0.0), false);
if (window_space.x >= area.x0) break;
}
// we should really really do a binary search rather than iterate
for (Points::size_type idx = 0; idx < c.n_samples - 1; ++idx) {
left = idx;
window_space = item_to_window (Duple (c.samples[idx].x, 0.0), false);
if (window_space.x >= area.x0) break;
}