User`s guide

issiso
11-107
11issiso
Purpose Test if an LTI model is single-input/single-output (SISO)
Syntax boo = issiso(sys)
Description issiso(sys) returns 1 (true) if the LTI model sys is SISO and 0 (false)
otherwise.
See Also isempty True for empty LTI models
size I/O dimensions and array dimensions of LTI models