"it is not working."
... because it is badly wrritten, badly aligned, badly designed code.
Sorry, but that code should be thrown away and replaced with simpler, more efficient code that actually uses arrays and indexing properly. It is a complete waste of MATLAB to use eval for every trivial operation and for accessing data. That code calls eval seven times, on nearly half of the code lines, which is very bad design makes the code slow, complex, obfuscated, buggy, and very difficult to debug, and is exactly why the MATLAB documentation and all experienced users recommend avoiding writing such pointlessly slow, complex, buggy code like this:
You need to learn how to use arrays.
You need to learn how to use indexing.
You need to avoid eval for such trivial code like this.
Start by doing the introductory tutorials, which show how to create and access data in arrays (and don't use eval at all):
