I implement bootci function in for loop and I get the error " not enough input argument"

Here is my code:

t=0:.1:pi;

y=sin(t);

a=[1 2 3 4];

b=[4 5 6 7];

c=[8 9 10 11];

d=[12 13 14 15]

for i=1:length(a)

beta0(i,:)=[a(i) b(i) c(i) d(i)];

x=t';

s_i{i}=@(x) a(i)*(x-t(i)).^3+b(i)*(x-t(i)).^2+c(i)*(x-t(i))+d(i);

modelfunc(i)=s_i{i};

beta(i) = @(predictor,response)nlinfit(predictor,response,modelfunc(i),beta0(i,:))

c(:,k) = bootci(1000,{beta(i),t',y},'Type','norm');

k=k+2;

end