function plot_switch(s,h,A,B)
%
%  plot_switch(s,h,A,B) plots a switch,
%  of size s and relative height h,
%  starting at position A and ending at B.
%
%  ON ENTRY:
%    s      size of the switch is the gap;
%    h      relative height of the switch,
%           the height of the opening is h*s; 
%    A      x and y coordinates of start position;
%    B      x and y coordinates of end position.
%
%  EXAMPLE:
%    plot_switch(0.4,1.2,[1,1],[2,1])
%    axis([0 3 0 2]);
%
x1 = [-1,-0.5*s,0.5*s];  % first leg -/
y1 = h*[0,0,0.5*s];
x2 = [0.5*s,1];          % second leg -
y2 = [0,0];
if(ishold == 0) 
   hold on;
end;
[xx1,yy1] = coordinate_transformation(x1,y1,A,B);
[xx2,yy2] = coordinate_transformation(x2,y2,A,B);
plot(xx1,yy1);
plot(xx2,yy2);