isnan(3C)            COMPATIBILITY FUNCTIONS            isnan(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);

     fpclasst fpclass (double dsrc);

     int unordered (double dsrc1, double dsrc2);

     #include <math.h>

     int isnan (double dsrc);

DESCRIPTION
     isnan, isnand, and isnanf return true (1)  if  the  argument
     dsrc or fsrc is a NaN; otherwise they return false (0).  The
     functionalty of isnan is identical to that of isnand.

     isnanf is implemented as a macro included  in  the  ieeefp.h
     header file.

     fpclass returns the class the dsrc belongs to.  The 10  pos-
     sible classes are as follows:
          FPSNAN      signaling NaN
          FPQNAN      quiet NaN
          FPNINF      negative infinity
          FPPINF      positive infinity
          FPNDENORM   negative denormalized non-zero
          FPPDENORM   positive denormalized non-zero
          FPNZERO     negative zero
          FPPZERO     positive zero
          FPNNORM     negative normalized non-zero
          FPPNORM     positive normalized non-zero

     finite returns true (1) if  the  argument  dsrc  is  neither
     infinity nor NaN; otherwise it returns false (0).

     unordered 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 of the arguments is NaN, false (0) is returned.

     None of these routines generate any exception, even for sig-
     naling NaNs.



          Last change: C Programming Language Utilities         1

isnan(3C)            COMPATIBILITY FUNCTIONS            isnan(3C)



SEE ALSO
     fpgetround(3C), intro(3M).





















































          Last change: C Programming Language Utilities         2