How to make a discrete x-y plot with quiver instead of stem

Hi,

I'm a matlab newbie. I made a simple X-Y plot with the stem command:

x=linspace(-10,10); x= -10:1:10; a= [0,0,0,0,0,0,0,0,0.5,0,0,0,0.5,0,0,0,0,0,0,0,0];

stem(x,a);

grid on;

But I'd like to get rid of the "circles" (points with y=0) and also add arrows to the vertical lines at x=-1 and x=+1).

I tried to use the quiver command without success. Can someone post some sample code using quiver (or stem if quiver can't do this)?

Thank you.

Answer 1

[A Jenkins]

Using quiver() as requested:

x= -10:1:10; 
a= [0,0,0,0,0,0,0,0,0.5,0,0,0,0.5,0,0,0,0,0,0,0,0];
y=zeros(size(x));
v=zeros(size(x));

% yaxis matches but "ugly" arrowhead
figure(1)
quiver(x,y,v,a,0)

% yxis does not match but better arrowhead
figure(2)
quiver(x,y,v,a,2)

Compare figure(1) and figure(2). If you care about the arrowhead size versus y-axis scaling, you may want to check out the file exchange for a solution:

http://www.mathworks.com/matlabcentral/fileexchange/34305-adjust-quiver-arrowhead-size

[Kim]

Thank you!