# finite(3C)

```

```

## NAME

```     isnan, isnand, isnanf, finite, fpclass, unordered  -  deter-
mine type of floating-point number

```

## SYNOPSIS

```     #include <ieeefp.h>

int isnand(double dsrc);

int isnanf(float fsrc);

int finite(double dsrc);

fpclass_t fpclass(double dsrc);

int unordered(double dsrc1, double dsrc2);

#include <math.h>

int isnan(double dsrc);

```

## DESCRIPTION

```     The isnan() function is identical to the isnand() function.

The isnanf() function is implemented as a macro included  in

The fpclass() function returns one of the following  classes
to which dsrc belongs:

FP_SNAN
signaling NaN

FP_QNAN
quiet NaN

FP_NINF
negative infinity

FP_PINF
positive infinity

FP_NDENORM
negative denormalized non-zero

FP_PDENORM
positive denormalized non-zero

FP_NZERO
negative zero

FP_PZERO
positive zero

FP_NNORM
negative normalized non-zero

FP_PNORM
positive normalized non-zero

None of these routines generates an exception, even for sig-
naling NaNs.

```

## RETURN VALUES

```     The isnan(), isnand(), and isnanf() function return TRUE (1)
if  the  argument  dsrc  or  fsrc  is a NaN;  otherwise they
return FALSE (0).

The finite() function returns TRUE (1) if the argument  dsrc
is  neither  infinity  nor  NaN; otherwise it returns  FALSE
(0).

The unordered() function returns TRUE (1) if one of its  two
arguments is unordered with respect to the other argument.
This is equivalent to reporting whether either argument  is
NaN.  If neither argument is NaN, FALSE (0) is returned.

```

## ATTRIBUTES

```     See attributes(5) for descriptions of the  following  attri-
butes:

____________________________________________________________
|       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
|_____________________________|_____________________________|
| MT-Level                    | MT-Safe                     |
|_____________________________|_____________________________|

```

```     fpgetround(3C), attributes(5)