Matching Intervals

There are four ways of matching intervals between source and target Interval files:

LONGEST The length of the Source file intervals within the Target file interval, are compared and values from the longest of those intervals are merged.
FIRST Values from the first interval in the Source file that includes any part of the Target file interval are merged.
LAST Values from the last interval in the Source file that includes any part of the Target file interval are merged.
MIDDLE Values from the interval that includes the middle value of the Target file interval are merged.

Each alternative is covered in the following diagrams: