You need to define the "Ldq" variable array of size 1x2, before the simulation starts.
Either you can create variable manually in MATLAB command window:-
Or you can add the above command in the "InitFcn" of the model file.
Open your .slx simulink file -> right click (keeping curson on white space in model file window) -> select "Model Properties" -> In "Model Properties" window go to "Callbacks" tab -> Select "InitFcn" under "Model Callbacks" -> Enter your code.
Code written in "InitFcn" will be executed first once the Run button is hit for simulation.