isnan(3C)                                                  isnan(3C)


       NAME
             isnan, isnand, isnanf, finite, fpclass, unordered - determine
             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
             isnan, isnand, and isnanf return true (1) if the argument dsrc
             or fsrc is NaN; otherwise they return false (0).  The
             functionality 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 that dsrc belongs to.  The 10
             possible classes are as follows:

                   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

             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.



                           Copyright 1994 Novell, Inc.               Page 1

      isnan(3C)                                                  isnan(3C)


            None of these routines generates exceptions, even for
            signaling NaNs.

      REFERENCES
            fpgetround(3C), intro(3)











































                          Copyright 1994 Novell, Inc.               Page 2