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: newuob.m
    path of file: ./repos/prima/benchmark/rescue_idz/norma/matlab/interfaces/+newuoa_norma_mat/private
    
    the code of the file until where you have to start completion: function [x, nf, f, fhist, xhist, info] = newuob(calfun, iprint, maxfun, npt, eta1, eta2, ftarget, gamma1, gamma2, rhobeg, rhoend, x, maxfhist, maxxhist, debugflag)
    n = length(x);
    xhist = NaN(n, maxxhist);
    % NEWUOB performs the
    
function evaluations with the current RHO.
            dnormsav = [dnormsav(2:length(dnormsav)); dnorm];

            % MODERR is the error of the current model in predicting the change in F due to D.
            moderr = f - fopt - qred;
            % MODERRSAVE is the prediction errors of the latest 3 models with the current RHO.
            moderrsav = [moderrsav(2:length(moderrsav)); moderr];

            % Calculate the reduction ratio and update DELTA accordingly.
            if isnan(qred) || qred >= 0
                info = infos('trsubp_failed');
                break;
            end