Requires a matrix with 4 named columns as datsteps will hand to the function: * "index" (identifier so the values can later be reassigned to their ID and variable), * "datmin" (minimum dating as any kind of number), * "datmax" (maximum dating as any kind of number), * "weight" (as created by get.weights), * "step" (empty). It's expected that dates BCE are displayed as negative values while dates CE are positive values. Ignoring this will cause problems in any case, that would be fixed automatically by switch.dating().
create.sub.objects(DAT_mat, stepsize)a matrix with 3 variables as prepared by datsteps()
Number of years that should be used as an interval for creating dating steps.
a longer matrix of the same structure to be further processed by datsteps() with a number of steps for each object