Error about A(I) = B?

Hi. I was wondering why I get this error

??? In an assignment A(I) = B, the number of elements in B and

 I must be the same.

Error in ==> detection_control_3_19_2014 at 194

          [f1(i) f2(i)] =

          control_forces(x(i),y(i),theta(i),Cc,xd_d(i),xdd_d,xddd_d,yd_d(i),ydd_d,yddd_d,t(i));

[dpb]

Because they're not? (the same size, that is).

A(i) is an element of A, B is an array or vector.

You need an addressing expression on the left that's the same size as

size(B)

to assign to an array unless you make it a cell array by encapsulating B in the curly braces "{}"