问请解释此倍频程错误代码: op1为1x12，op2为1x3

EN

function result = assess_polynomial_n(y,n)

    [coeff, t, pred_accum] = fit_data(y, n);
    [avg, std_dev] = compute_error(coeff,y);
    [coeff1, t, pred_accum1] = fit_data(y, n+1);
    [avg1, std_dev1] = compute_error(coeff1,y);
    if avg1>avg
        result = n;
    elseif avg<0.1 && std_dev<0.1
        result = n;   
    elseif pred_accum1.*(1)<0.0001
        result = n;
    else
        result = 0;
    end
end

***Error***
error: compute_error: operator -: nonconformant arguments (op1 is 1x12, op2 is 1x3)
error: called from
    compute_error at line 11 column 17
    assess_polynomial_n at line 19 column 18
    __tester__.octave at line 38 column 1

function [coeff, t, pred_accum] = fit_data(y, n)
    len = length(y);
    t = 10*[0:len-1];
    coeff = polyfit(t, y, n);
    pred_accum = polyval(coeff, t);
end

function [avg std_dev] = compute_error(x,y)
    s=[];
    for i=1:length(x)
        error=abs(x(i)-y(i));
        s=[s,error];
    end
    avg = mean(s);
    std_dev = std(s);
end