ScatPlotPoint := proc () 
local X, Y, N, A, Minx, Maxx, Miny, Maxy, XR, YR, EX, EY, i; 
option `January 27, 1994 -- Zaven A. Karian, June 28, 1999, Elliot Tanis`; 
description `Produce a scatter plot of X-Y pairs`; 
if nargs = 1 and not type(args[1],listlist) then ERROR(`When one argument is used it must be a list of lists`) fi; 
if nargs = 2 and not (type(args[1],list) and type(args[2],list)) then ERROR(`When two arguments are used, both must be lists`) fi; if nargs = 2 and nops(args[1]) <nops(args[2]) then ERROR(`The two lists must have the same length`) fi; 
if nargs = 1 then X := [seq(args[1][i][1],i = 1 .. nops(args[1]))]; Y := [seq(args[1][i][2],i = 1 .. nops(args[1]))] else X := args[1]; Y := args[2] fi; 
N := nops(X); 
A := array(1 .. 2*N); 
for i to N do A[2*i-1] := X[i]; 
 A[2*i] := Y[i] 
od; 
Minx := Min(X); 
Maxx := Max(X); 
Miny := Min(Y); Maxy := Max(Y); 
EX := 1/20*Maxx-1/20*Minx; 
EY := 1/20*Maxy-1/20*Miny; 
XR := Minx-EX .. Maxx+EX; 
YR := Miny-EY .. Maxy+EY; 
plot([seq([A[2*i-1], A[2*i]],i = 1 .. N)],XR,YR,style=POINT,symbol = POINT, color=black) 
end: