dev-cpp-users

[Dev-C++] Checking validity of float and double

[Glen C. <gc...@pa...>]

This isnt a dev-C++ specific question, but i am wondering if anyone =
knows how you check if a float or double carrys valid data.=20

My program runs fine most of the time but every now and again it spits =
out -NaN.
I figure its from uninitialised variables, however I cant track down =
where they enter the program without performing periodick checks at =
suspect locations.=20

So is there a function like=20
    bool validFloat(float num)  for instance?

Re: [Dev-C++] Checking validity of float and double

[<jar...@ig...>]

On 26 Apr, Glen Corby wrote:
> This isnt a dev-C++ specific question, but i am wondering if anyone knows how you check if a float or double carrys valid data. 
> 
> My program runs fine most of the time but every now and again it spits out -NaN.
> I figure its from uninitialised variables, however I cant track down where they enter the program without performing periodick checks at suspect locations. 
> 
> So is there a function like 
>     bool validFloat(float num)  for instance?


Here a function from the open SciLab system (matlab clone)
try this

int mxIsNaN(double x)
{
  if ( x != x ) 
    return 1;
  else return 0;
}


-- 
Helmut Jarausch

Lehrstuhl fuer Numerische Mathematik
Institute of Technology, RWTH Aachen
D 52056 Aachen, Germany

RE: [Dev-C++] Checking validity of float and double

[Ioannis V. <no...@ho...>]

What would be valid data for a float and how it would differ from the
random data stored in an unitialised one?
 
 
Ioannis

* Ioannis Vranos
* Programming pages: http://www.noicys.cjb.net
<http://www.noicys.cjb.net/> 
* Alternative URL: http://run.to/noicys

-----Original Message-----
From: dev...@li...
[mailto:dev...@li...] On Behalf Of Glen
Corby
Sent: Friday, April 26, 2002 12:49 PM
To: dev...@li...
Subject: [Dev-C++] Checking validity of float and double


This isnt a dev-C++ specific question, but i am wondering if anyone
knows how you check if a float or double carrys valid data. 
 
My program runs fine most of the time but every now and again it spits
out -NaN.
I figure its from uninitialised variables, however I cant track down
where they enter the program without performing periodick checks at
suspect locations. 
 
So is there a function like 
    bool validFloat(float num)  for instance?

RE: [Dev-C++] Checking validity of float and double

[Ioannis V. <no...@ho...>]

What would be valid data for a float and how it would differ from the
random data stored in an unitialised one?
 
 
Ioannis

* Ioannis Vranos
* Programming pages: http://www.noicys.cjb.net
<http://www.noicys.cjb.net/> 
* Alternative URL: http://run.to/noicys

-----Original Message-----
From: dev...@li...
[mailto:dev...@li...] On Behalf Of Glen
Corby
Sent: Friday, April 26, 2002 12:49 PM
To: dev...@li...
Subject: [Dev-C++] Checking validity of float and double


This isnt a dev-C++ specific question, but i am wondering if anyone
knows how you check if a float or double carrys valid data. 
 
My program runs fine most of the time but every now and again it spits
out -NaN.
I figure its from uninitialised variables, however I cant track down
where they enter the program without performing periodick checks at
suspect locations. 
 
So is there a function like 
    bool validFloat(float num)  for instance?

RE: [Dev-C++] Checking validity of float and double

[David M. <ci...@ya...>]

here is a idea 
initalize your variables when you declare them
eg float var_name = 0.0;
thus you can test for for 0 to see if the values
have changed.

> From: dev...@li...
> [mailto:dev...@li...] On
> Behalf Of Glen
> Corby
> Sent: Friday, April 26, 2002 12:49 PM
> To: dev...@li...
> Subject: [Dev-C++] Checking validity of float and double
> 
> 
> This isnt a dev-C++ specific question, but i am wondering
> if anyone
> knows how you check if a float or double carrys valid
> data. 
>  
> My program runs fine most of the time but every now and
> again it spits
> out -NaN.
> I figure its from uninitialised variables, however I cant
> track down
> where they enter the program without performing periodick
> checks at
> suspect locations. 
>  
> So is there a function like 
>     bool validFloat(float num)  for instance?

=====
David Mcken

Life Sucks
Live with it

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