Usage:
arrowflow(x,y,sx,sy,r);
Input:
x,y : initial position coordinates
default is 0,0
sx,sy : scaling of arrows along x and y coordinates
as a percentage of axis length, e.g. 10%
default is 10,10
r : angle of rotation
r=1 --> East-North
r=2 --> North-West
r=3 --> West-South
r=4 --> South-East
default is 1

Output:
h : handles of plot of the arrows
Example:
figure;
plot(0:0,1:1);
plot(0:1,1:0);
arrowflow(1/3,2/3,0,0,1);
arrowflow(2/3,2/3,0,0,3);

Issues:
To keep arrows of same length requires:axis square;