[Matrix-SIG] Generating NaN and catching exceptions

[Yoon, Hoon (CICG - NY Program Trading)]

Hi,

  I was wondering how can I generate and use Python NaN's from  my CXX code.
Currently I am using the code below: (which generates this 1.#QNAN thing in
NT)
  I would like to change it to what I generate for Python by 
INF = 1e1000**1000000
NA  = (INF/INF)
   I try passing in this to Cxx extension as arg, but that does not quite
work. Not to mention that I would like to assign this a variable rather than
function call. pyRTL.NA &  not NA = pyRTL.mkMsg()
  I guess I am really looking for what's equivalent to what's in #define
ISMISSING and MKMISSING.

  One other thing is I tried,   catch(const Exception&) {   // Catch
ValueError?
  but what I really want is catch(const ValueError&) whenever I pass in
something like a String, as arg to ex_tst_msg(), but it does not seem to
catch it. I thought that was strange, but C++ is a tempermental mistress.
  Any sample code or help will be appreciated greatly!

hn_rtl.h file---------
//Unix Missing Values
//#define ISMISSINGVAL(A) ( (*((unsigned short *)(A)) & (unsigned
short)0x7FFF) > (unsigned short)0x7FF0 )
//#define MKMISSINGVAL(A)   ( *((unsigned int *)(A)) = 0x7fffffff,
*((unsigned int *)(A)+1) = (unsigned int)0 )

// NT missing
#define ISMISSINGVAL(A)   ( (*((unsigned short *)(A)+3) & (unsigned
short)0x7FFF) > (unsigned short)0x7FF0 )
#define MKMISSINGVAL(A)   ( *((unsigned int *)(A)+1) = 0x7fffffff,
*((unsigned int *)(A)) = (unsigned int)0 )

in my cxx prg-----------------
static Float
mkMsg() {
	double *msgV;
	double msgv;
	msgv  = 0.0;
	msgV = &msgv;
	MKMISSINGVAL(msgV);
	return Float(msgv);
}

static PyObject *
ex_mkMsg(PyObject* self, PyObject* args) {
	return new_reference_to(mkMsg());
}

static PyObject *
ex_tst_msg(PyObject* self, PyObject* args) {
  try {
	Tuple tArgs(args);
	Float isMsgV = Float(tArgs[0]);
	double msgv = (double) isMsgV;
	double *msgV = &msgv;
	if ISMISSINGVAL(msgV) return new_reference_to(Int(1));
	else return new_reference_to(Int(0));
	//	if (NAval == isMsgV) return new_reference_to(Int(0));
  }
  catch(const Exception&) {   // Catch ValueError?
	return new_reference_to(Int(0));
	//cout << "Exception in clearing all ref.\n";
	//return Null ();
  }
}

**************************************************************
S. Hoon Yoon                   (Quant)                    Merrill Lynch
Equity Trading 
yelled@yahoo.com hoon@bigfoot.com(w)
"Miracle is always only few standard deviations away, but so is
catastrophe."
* Expressed opinions are often my own, but NOT my employer's.
"I feel like a fugitive from the law of averages."    Mauldin
**************************************************************