You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: spm_nvc_gen.m
    path of file: ./repos/spm12/toolbox/NVC
    
    the code of the file until where you have to start completion: function [y] = spm_nvc_gen(P,M,U)
% Generate a BOLD signal prediction from scaled summed of neuronal drives 

    
function [y] = spm_nvc_gen(P,M,U)
% Generate a BOLD signal prediction from scaled summed of neuronal drives 
% (neurovascular coupling).
% FORMAT [y] = spm_nvc_gen(P,M,U)
%
% Inputs:
% -------------------------------------------------------------------------
%  P - parameters of neurovascular coupling and Extend