Lasttoggle
A data structure used by tergm for tracking of limited information about dyad edge histories.
The tergm package handles durational information attached to network objects by way of the time and lasttoggle network attributes. The lasttoggle data structure is a 3-column matrix; the first two columns are tails and heads (respectively) of dyads, and the third column is the last time at which the dyad was toggled. The default last toggle time is -INT_MAX/2. Last toggle times for non-edges are periodically cleared in the C code. The time network attribute is simply an integer, and together with the lasttoggle data it determines the age of an extant tie as time + 1 minus the last toggle time for that dyad. The default value for time is 0.