Dear Allstaters, I appreciate very much telling me about the Minitab commands to plot a left step function c2 against c1 where, e.g. c1 c2 0 1 1 .9 2 .7 The plot should look like: 1 ___ .9 |____ | .7 |______ | Minitab commands to do this will be included in a macro. Thanks in advance. M.E. Ghitany 1/5/Y2K %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%