\def\pole{{\setcoordinatesystem units <.2in,.2in>
	\plot -.2 -.2 .2 .2 / \plot -.2 .2 .2 -.2 /}}
\def\zero{{\setcoordinatesystem units <.2in,.2in>
	\circulararc 360 degrees from 0 0 center at -.25 0 }}

\def\putzero#1#2{\put{\zero} at #1 #2}
\def\putpole#1#2{\put{\pole} at #1 #2}

% x-units, y-units, xmin, xmax, ymin, ymax, xticksquant, yticksquant

\def\beginpz#1#2#3#4#5#6#7#8{
\beginpicture
\setcoordinatesystem units <#1,#2>
\setplotarea x from #3 to #4, y from #5 to #6
\axis bottom shiftedto y=0 ticks withvalues #7 /
\axis right shiftedto x=0 ticks withvalues #8 /
}

\def\endpz{\endpicture}

% DT diagrams

\def\putdtval#1#2{{\plot #1 0 #1 #2 / \setplotsymbol({$\bullet$})
\plot #1 #2 #1 #2 /}}

% x-units, y-units, xmin, xmax, ymin, ymax, xticksquant, yticksquant

\def\begindt#1#2#3#4#5#6#7#8{
\beginpicture
\setcoordinatesystem units <#1,#2>
\setplotarea x from #3 to #4, y from #5 to #6
\axis bottom shiftedto y=0 ticks withvalues #7 /
\axis right shiftedto x=0 ticks withvalues #8 /
%\newdimen\dimenx
%\newdimen\dimeny
%\dimenx=#1
%\dimeny=#1
%\advance\dimenx by -.07in
%\advance\dimeny by -.07in
\setcoordinatesystem units <.345in,.4in> point at .31 0
}

\def\enddt{\endpicture}
