How to define an arbitrary array of chebfun in matlab?

For example, I will like to be able to create multiple chebfun's in the following way,

chebfun('x', [0,1]);
for i=1:3
f(i) = sin(i*pi*x);
end

How would I define f(i)?

I understand that a definition of the form

f = [sin(pi*x) sin(2*pi*x) sin(3*pi*x)];

would define a quasi-matrix, each column of length infinity. However, I cannot pre-allocate a matrix of

f = zeros(inf,3).