2 ismat - whether a value is a matrix
13 Determine if x is a matrix. This function will return 1 if x is
14 a matrix, 0 otherwise.
18 > print ismat(a), ismat(1)
28 mat, matdim, matfill, matmax, matmin, matsum, mattrans,
29 isassoc, isatty, isblk, isconfig, isdefined, iserror, iseven, isfile,
30 ishash, isident, isint, islist, ismult, isnull, isnum, isobj,
31 isobjtype, isodd, isprime, isrand, israndom, isreal, isrel,
32 issimple, issq, isstr, istype