// Some xarrow stuff
// and graphics demo
scf(0); // open graphics window 0 (if it is not already open)
clf(); // clear it
t=0:0.1:1;
y=t.*(1-t); 
plot(t,y,'b*-')
xtitle("y = t(1-t) in blue and matching arrow","t","y");
xarrows([0.1,0.2],[0.2,0.1],1,2) // the 2 is blue, the 1 is the size of arrowhead
//
scf(1); // open graphics window 1 (if it is not already open)
clf(); // clear it
plot(t,y,'rs-')
xtitle("y = t(1-t) in red and matching arrow","t","y");
xarrows([0,0.5],[0,0.25],1,5) // the 5 is red, the 1 is the size of arrowhead
//
scf(2); // open graphics window 2 (if it is not already open)
clf(); // clear it
plot(t,y,'gd-')
xtitle("y = t(1-t) in green and matching arrow","t","y");
xarrows([0.5,0],[0.25,0],1,3) // the 3 is green? the 1 is the size of arrowhead