Absolute distances are scaled by the inter-reference gap for the
chromosome as follows. For Q query points and R reference
points on a chromosome, scale the distance for each query point i to
the closest reference point by the inter-reference gap for each chromosome.
If an x interval has no matching y chromosome,
.absdist is NA.
$$d_i(x,y) = min_k(|q_i - r_k|)\frac{R}{Length\ of\ chromosome}$$
Both absolute and scaled distances are reported as .absdist and
.absdist_scaled.
Interval statistics can be used in combination with
dplyr::group_by() and dplyr::do() to calculate
statistics for subsets of data. See vignette('interval-stats') for
examples.