Having trouble with "Index exceeds the number of array elements (1)" error

If someone could help me to get this code working without error it would be greatly appreciated!

%Question 5: Robot Arm
ang01=input('Starting angle 1: ');
ang02=input('Starting angle 2: ');
angt1=input('Final angle 1: ');
angt2=input('Final angle 2: ');
tf=input('Final time (tf): ');
L1=input('Length 1 (L1): ');
L2=input('Length 2 (L2): ');

ang1=angt1-ang01;
ang2=angt2-ang02;
tmat=[tf^3,tf^4,tf^5];
a=pinv(tmat).*ang1;
b=pinv(tmat).*ang2;

disp(['a1: ',num2str(a(1))]);
disp(['a2: ',num2str(a(2))]);
disp(['a3: ',num2str(a(3))]);
disp(['b1: ',num2str(b(1))]);
disp(['b2: ',num2str(b(2))]);
disp(['b3: ',num2str(b(3))]);

angt1r=(pi/180)*angt1;
angt2r=(pi/180)*angt2;

x=L1*cosd(angt1r)+L2*cosd(angt1r+angt2r);
y=L1*sind(angt1r)+L2*sind(angt1r+angt2r);

t=0:0.01:2;
ax=gca;

for k=1:numel(t)
    M=line([0,L1*cosd(angt1r(k)),x(k)],[0,L1*sind(angt1r(k)),y(k)]);
    T=line(x(1:k),y(1:k));
    pause(0.05)
    if k~=numel(t)
        delete(M)
        delete(T)
    end
    
end

Answer 1

[per isakson]

The error occur in the line

M=line([0,L1*cosd(angt1r(k)),x(k)],[0,L1*sind(angt1r(k)),y(k)]);

Here the variables angt1r, x and y are scalars.

>> whos angt1r  x  y
  Name        Size            Bytes  Class     Attributes
  angt1r      1x1                 8  double              
  x           1x1                 8  double              
  y           1x1                 8  double            

Thus for k>=2 the error will occur.

See Debug a MATLAB Program and Examine Values While Debugging