HELP! Koch Square Error: A(I): index out of bounds; value 4 out of bound 3

I don't know why I'm getting this error. Can anyone please tell me the problem and how to fix it?

[Alexandra Harkai]

Duplicate of this, which is a duplicate already.

Answer 1

[KSSV]

Check this line in your code:

   v=[newpointsx(4);newpointsy(4)]-[newpointsx(2);newpointsy(2)]

you have defined newpointsx(1),newpointsx(2) and newpointsx(3) but you have not defined newpointsx(4) and you are trying to call/ use it in v. Same thing with newpointsy, so the error is popping out. Define newpointsx(4) and newpointsy(4) before/ above v.