Time for action - checking user inputs and outputs

1. 1. Code Listing 8.2 shows an example of a function called args. This function takes any number of inputs, checks what type they are, and writes this to the Octave command prompt. It returns a sequence of numbers going from 1 to the number of input arguments:

   Code Listing 8.2
   #include <octave/oct.h> #1
   #2
   #define HELP_TEXT "Usage:[out1,out2,...]=args(in1,in2,...)" #3
   #4
   DEFUN_DLD(args, argv, nargout, HELP_TEXT){ #5
   octave_value_list retval; #6
   #7
   int nargs = argv.length(); #8
   octave_stdout<<"You've entered "<< nargs << " argument(s)\n";#9
   #10
   if ( nargout > nargs ){ #11
   error("Number of output variables is too large"); #12
   return retval; #13
   } #14
   #15
   for ( int n=0; n<nargs; n++ ){ #16
   octave_stdout << "Argument " << n+1 << " is "; #17
   if ( argv(n).is_string() ) #18
   octave_stdout << "a text string "; #19
   if ( argv(n).is_real_scalar() ) #20
   octave_stdout << "a real scalar "; #21
   if...