How can I calculate the F and p Values for more than 2 numeric vectors with anovan?

How can I calculate the F and p Values for more than 2 numeric vectors with anovan? This is my code:

%load data
y = [52.7 57.5 45.9 44.5 53.0 57.0 45.9 44.0]';
g1 = [1 2 1 2 1 2 1 2];
g2=g1.*5;
g3=g1+7;
%create model
R={g1,g2,g3};
p = anovan(y,R);

But the table always gives this answer:

    Source   Sum Sq.   d.f.   Mean Sq.   F   Prob>F
  -------------------------------------------------
  # X1         0        0      0         0    NaN  
  # X2         0        0      0         0    NaN  
  # X3         0        0      0         0    NaN  
    Error    217.598    6     36.2663              
    Total    221.379    7

Earlier, I did it with anova1 for every y separately. Is there another possibility to combine this in one step than anovan?