Takes a data frame describing stratigraphic units and relations and turns it into a graph representation.
stratigraph(data, label, relation, direction = c("above", "below"))
Data frame of stratigraphic units, containing at least a unique label column and a column describing stratigraphic relations.
Name of the column containing labels of the stratigraphic units.
Name of the column describing the stratigraphic relations between units.
Direction described by