How can I re write a code in GUI?

Hello. I have a code and trying to convert it to GUI. For this purpose, I input some data and plot a graph. At plot section, I need to use my code. So, I rewrite whole of my code in this section and just changed the variables to handles.variable. For example if I have A=B+C in my code, I rewrite handles.A=handles.B+handles.C. However the GUI does not run and shows an error that the memory is not enough and the arrays are exceeded the limitations. I need you help please. Thanks