Definitions of horizontal and vertical dashed lines for the array and tabular environment. Instead of building partial horizontal dashed lines using Isozaki's \cline{2-3}, \hdashline fills the full width. The proportion of the dashed line is defined by the two parameters: \hdashlinewidth=2pt and \hdashlinegap=2pt, where the former defines the width of the dash and the latter sets their gap.

Note that this functionality has been re-implemented, for current LaTeX, in the package arydshln.