Command:

INFINITY(3) Linux Programmer's Manual INFINITY(3)NAMEINFINITY, NAN, HUGE_VAL, HUGE_VALF, HUGE_VALL - floating-point constantsSYNOPSIS#define_ISOC99_SOURCE#include<math.h>INFINITYNANHUGE_VALHUGE_VALFHUGE_VALLDESCRIPTIONThe macroINFINITYexpands to afloatconstant representing positive infinity. The macroNANexpands to afloatconstant representing a quiet NaN (when supported). AquietNaN is a NaN ("not-a-number") that does not raise exceptions when it is used in arithmetic. The opposite is asignalingNaN. See IEC 60559:1989. The macrosHUGE_VAL,HUGE_VALF,HUGE_VALLexpand to constants of typesdouble,floatandlongdouble, respec- tively, that represent a large positive value, possibly plus infinity.CONFORMINGTOC99.AVAILABILITYOn a glibc system, the macroHUGE_VALis always available. Availability of theNANmacro can be tested using#ifdefNAN, and similarly forINFINITY,HUGE_VALF,HUGE_VALL. They will be defined by<math.h>if_ISOC99_SOURCEor_GNU_SOURCEis defined, or__STDC_VERSION__is defined and has a value not less than 199901L.SEEALSOfpclassify(3), feature_test_macros(7), math_error(7)COLOPHONThis page is part of release 3.22 of the Linuxman-pagesproject. A description of the project, and informa- tion about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. 2007-07-26 INFINITY(3)