isnan(3C)                        DG/UX 5.4.2                       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 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 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.

       None of these routines generate any exception, even for signaling
       NaNs.





Licensed material--property of copyright holder(s)                         1

isnan(3C)                        DG/UX 5.4.2                       isnan(3C)


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























































Licensed material--property of copyright holder(s)                         2