Index exceeds the number of array elements. Please Help?

% Generates optimized trajectory for the robotics arm problem
function [] = generate_optimized_traj(x)
d1 = 66.04;
d3 = 14.91;
d4 = 43.31;
a2 = 43.18;
a3 = 2.03;
for i = 1:100
t = -pi + (i-1)*0.063;
theta1 = x(i);
theta2 = x(i+100);
theta3 = x(i+200);
c1 = cos(theta1);
c2 = cos(theta2);
s1 = sin(theta1);
s2 = sin(theta2);
c23 = cos(theta2+theta3);
s23 = sin(theta2+theta3);
f1(i) = c1*(a2*c2 + a3*c23 - d4*s23) - d3*s1;
f2(i) = s1*(a2*c2 + a3*c23 - d4*s23) + d3*c1;
f3(i) = d1 - a2*s2 - a3*s23 -d4*c23;
end
plot3(f1,f2,f3,'r*')
end

This is the code where the error is encountered. This appears on line 15 ( theta2=x(i+100) ).

The code above should generate the optimal trajectory for the arm of an industrial robot.

f1,f2 and f3 are kinetic equations.

Does anyone have any idea why i get the following error on line 15: Index exceeds the number of array elements (2).

Answer 1

[KALYAN ACHARJYA]

Read about array indexing, suppose you have x=[2 3 4], its having 3 length, if you want acess x(5), it will shows Index exceeds the number of array elements., because x have only three elements , hence

x(1) OK

x(2) OK

x(3) OK

..

x(4) Invalid ....

Beacuse , what you have pass the value of x, I have no idea, but you trying to access the more than 100 elements of x (i+100)..so on in for loop (100 iterration loop), is it?

Is this? Pass any 1 D array as x

function []=generate_optimized_traj(x)
d1 = 66.04;
d3 = 14.91;
d4 = 43.31;
a2 = 43.18;
a3 = 2.03;
for i=1:length(x)
t=-pi+(i-1)*0.063;
theta1=x(i);
theta2=x(i)+100;
theta3=x(i)+200;
c1 = cos(theta1);
c2 = cos(theta2);
s1 = sin(theta1);
s2 = sin(theta2);
c23 = cos(theta2+theta3);
s23 = sin(theta2+theta3);
f1(i) = c1*(a2*c2 + a3*c23 - d4*s23) - d3*s1;
f2(i) = s1*(a2*c2 + a3*c23 - d4*s23) + d3*c1;
f3(i) = d1 - a2*s2 - a3*s23 -d4*c23;
end
plot3(f1,f2,f3,'r*')
end

[Emil BUCUR]

Thank you very much. I saw where I was wrong.

Answer 2

[Guillaume]

Does anyone have any idea why i get the following error on line 15

Because the x you passed has less than 300 elements. Since i goes up to 100 and you try to access x(i+200), x needs to have at least 300 elements.