periodic least square meth

t=0:1/8:7/8;
y=[-2.2 -2.8 -6.1 -3.9 0 1.1 -0.6 -1.1]';
CCoef = @(t)[1 cos(2*pi*t) sin(2*pi*t)];
m = length(t);
n = length(CCoef(NaN));
A=zeros(m, n);
for i=1:m
    A(i,:) = CCoef(t(i));
end
%lsm
ATA = A'*A;
ATB=A'*y;
c = ATA\ATB;
predfn=@(t)c(1)+c(2)*cos(2*pi*t)+c(3)*sin(2*pi*t);
fplot(predfn, [0 1], 'red')
hold on
plot(t, y', '*')