isascii tests if character is a 7-bit US-ASCII character res = isascii(str) str a character string or an array of integers. res a boolean matrix. res = isascii(str) returns %t (TRUE) if entries of str are a 7-bit US-ASCII character code between 0 and octal 0177 inclusive (or entries of str are 7-bit US-ASCII characters). Otherwise returns %f (FALSE). isalphanum