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);

     fpclasst fpclass(double dsrc);

     int unordered(double dsrc1, double dsrc2);

     #include <math.h>

     int isnan(double dsrc);

DESCRIPTION
     isnan(), isnand(), and isnanf() return 1 if the argument dsrc or fsrc
     is a NaN; otherwise they return 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 the dsrc belongs to. The 10 possible
     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 1 if the argument dsrc is neither infinity nor NaN;
     otherwise it returns 0.

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





Page 1                       Reliant UNIX 5.44                Printed 11/98

isnan(3C)                                                         isnan(3C)

SEE ALSO
     fpgetround(3C).




















































Page 2                       Reliant UNIX 5.44                Printed 11/98