The function is as follows:
you can draw two-dimensional and three-dimensional, p0, p1 are the start and end points respectively
function vectarrow(p0,p1)
%Arrowline 3-D vector plot.
% vectarrow(p0,p1) plots a line vector with arrow pointing from point p0
% to point p1. The function can plot both 2D and 3D vector with arrow
% depending on the dimension of the input
%
% Example:
% 3D vector
% p0 = [1 2 3]; % Coordinate of the first point p0
% p1 = [4 5 6]; % Coordinate of the second point p1
% vectarrow(p0,p1)
%
% 2D vector
% p0 = [1 2]; % Coordinate of the first point p0
% p1 = [4 5]; % Coordinate of the second point p1
% vectarrow(p0,p1)
%
% See also Vectline
% Rentian Xiong 4-18-05
% $Revision: 1.0
if max(size(p0))==3
if max(size(p1))==3
x0 = p0(1);
y0 = p0(2);
z0 = p0(3);
x1 = p1(1);
y1 = p1(2);
z1 = p1(3);
plot3([x0;x1],[y0;y1],[z0;z1]); % Draw a line between p0 and p1
p = p1-p0;
alpha = 0.1; % Size of arrow head relative to the length of the vector
beta = 0.1; % Width of the base of the arrow head relative to the length
hu = [x1-alpha*(p(1)+beta*(p(2)+eps)); x1; x1-alpha*(p(1)-beta*(p(2)+eps))];
hv = [y1-alpha*(p(2)-beta*(p(1)+eps)); y1; y1-alpha*(p(2)+beta*(p(1)+eps))];
hw = [z1-alpha*p(3);z1;z1-alpha*p(3)];
hold on
plot3(hu(:),hv(:),hw(:)) % Plot arrow head
grid on
xlabel('x')
ylabel('y')
zlabel('z')
hold off
else
error('p0 and p1 must have the same dimension')
end
elseif max(size(p0))==2
if max(size(p1))==2
x0 = p0(1);
y0 = p0(2);
x1 = p1(1);
y1 = p1(2);
plot([x0;x1],[y0;y1]); % Draw a line between p0 and p1
p = p1-p0;
alpha = 0.1; % Size of arrow head relative to the length of the vector
beta = 0.1; % Width of the base of the arrow head relative to the length
hu = [x1-alpha*(p(1)+beta*(p(2)+eps)); x1; x1-alpha*(p(1)-beta*(p(2)+eps))];
hv = [y1-alpha*(p(2)-beta*(p(1)+eps)); y1; y1-alpha*(p(2)+beta*(p(1)+eps))];
hold on
plot(hu(:),hv(:)) % Plot arrow head
grid on
xlabel('x')
ylabel('y')
hold off
else
error('p0 and p1 must have the same dimension')
end
else
error('this function only accepts 2D or 3D vector')
end
