Index in position 2 exceeds array bounds (must not exceed 1). Error can't seem to find the mistake

So I recently tried changing the arrow head visuals through annotations, the following code is a modified one, and everytime I run it, it returns an 'exceed array bounds' error I already double checked everything, but I still can't find the problem as I already individually call the variables and check their array dimensions and everything check out. Any ideas why?

p = y(:,3);
o = y(:,4);
u = cos(p).*o;
v = sin(p).*o;

quiver(p,o,u,v,'r');

headWidth = 3;
headLength = 3;
LineLength = 0.03;

U = hq.UData;
V = hq.VData;
X = hq.XData;
Y = hq.YData;

hax_2 = subplot(1,2,2);

for ii = 1:length(X)
    for ij = 1:length(X)

        headWidth = 3;
        ah = annotation('arrow',...
            'headStyle','cback1','HeadLength',headLength,'HeadWidth',headWidth);
        set(ah,'parent',gca);
        set(ah, 'position', [X(ii,ij) Y(ii,ij) U(ii,ij) V(ii,ij)])

    end
end

Answer 1

[KSSV]

You have to specify the dimensions of row and column of a matrix. You should use Size. You have used length and it is creating problem . Length will give you the maximum of length of row or column.

p = y(:,3);
o = y(:,4);
u = cos(p).*o;
v = sin(p).*o;

quiver(p,o,u,v,'r');

headWidth = 3;
headLength = 3;
LineLength = 0.03;

U = hq.UData;
V = hq.VData;
X = hq.XData;
Y = hq.YData;

hax_2 = subplot(1,2,2);

for ii = 1:size(X,1)   % USe rows here 
    for ij = 1:size(X,2)  %USe columns here 

        headWidth = 3;
        ah = annotation('arrow',...
            'headStyle','cback1','HeadLength',headLength,'HeadWidth',headWidth);
        set(ah,'parent',gca);
        set(ah, 'position', [X(ii,ij) Y(ii,ij) U(ii,ij) V(ii,ij)])

    end
end