emptystr zero length string s = emptystr() s = emptystr(a) s = emptystr(m, n) a a matrix of size mx n. s a matrix of character strings. m, n integers The emptystr function returns a matrix of zero length character strings. With no input argument emptystr returns a zero length character string. With a matrix a for input argument emptystr returns a zero length character strings matrix of the same size. With two integer arguments emptystr returns a m x n zero length character strings matrix. part length string