DDLab may keep a record of the frequency of different in-degrees (the number of pre-images or predecessors) that occur in a subtree, basin or field. If this option is selected, the in-degree information is displayed as a histogram when the attractor basin is finished (whether complete or interrupted). In the case of a subtree, the in-degree histogram may also be displayed during a temporary interrupt (see #25.1). The following prompt is presented,
show pre-image frequency histogram-y
If ``y'' is entered, the histogram setting remains for all further attractor basins. It may be deactivated above, by restoring all ``output parameter'' defaults (see #16.1.3), or by backtracking through the main prompt sequence beyond #8.