How to compute the coset C of A w.r. to I ( where I is the union of C and A)

Hello, does somebody know a function which gives me the Coset C of A(subset I), such that I is the union of C and A (as set)

e.g., input I=[1,2,3,4,5] , A = [1,2,4]

output C=[3,5]

Answer 1

[James Tursa]

Is this what you want?

 C = I(~ismember(I,A));

[Daniel Miller]

Yes, thank you

Answer 2

[Steven Lord]

I think you want the setdiff of the two vectors.