// example vpointer script
// reads in all 3D/4D vars and converts them to float 
// after conversion  
// for each var processed
// creates a range attribute that contains min/max
// creates a total attribtes that contains the sum of the elements


// The regular NCO attribute definition is var_nm@all_nm - but if "var_nm" is missing 
// then it is defaulted  to "global" 
// This  function reads in all vars in Input and ouptuts them as a ragged array
// which is in NetCDF lingo is a NC_STRING att
// to see  the NC_STRING att the ouptut file type must be NetCDF-4
@all=get_vars_in();

*sz=@all.size();


for(*idx=0;idx<sz;idx++)
{

  // To use an atrribute as a "pointer" - it must be a text type (NC_CHAR and NC_STRING) -The text it contains is 
  // a var name or an att name -  by prefixing this att with a '*' we are saying "treat me as a variable" 
  // the '*' has the highest presedence of the operators in NCAP2 so for example
  //  *global@var_nm.total() is equivalent to (*global@var_nm).total() 
  @var_nm=@all(idx);
  // works similar to  to a printf() 
  print(@var_nm,"about to test %s\n");
  if(*@var_nm.ndims()>=3 )
  {
    // This is where the magic happens the '*' says make me a variable !!
    *@var_nm=*@var_nm.float();
    // The push function also takes a call-by-ref att -if it  doesnt already exist then it is created
    // the call below is pushing a NC_STRING to an att so the end result is a list of NC_STRINGS   
    push(&@prc,@var_nm); 
  }

} 


*sz=@prc.size();


for(*idx=0;idx<sz;idx++)
{
  @var_nm=@prc(idx);

  // we can work with att pointers as well 
  // sprint - ouptut is of type NC_CHAR
  @att_total=sprint(@var_nm,"%s@total"); 
  @att_range=sprint(@var_nm,"%s@range"); 
 
  *@att_total= *@var_nm.total();
  *@att_range={ min(*@var_nm), max(*@var_nm)}; 


} 




