NAN(3) NAN(3) NAME NaN, Inf, isNaN, isInf - not-a-number and infinity functions SYNOPSIS #include <u.h> #include <libc.h> double NaN(void) double Inf(int) int isNaN(double) int isInf(double, int) DESCRIPTION The IEEE floating point standard defines values called `not-a-number' and positive and negative `infinity'. These values can be produced by such things as overflow and divi- sion by zero. Also, the library functions sometimes return them when the arguments are not in the domain, or the result is out of range. NaN returns a double that is not-a-number. IsNaN returns true if its argument is not-a-number. Inf(i) returns positive infinity if i is greater than or equal to zero, else negative infinity. IsInf returns true if its first argument is infinity with the same sign as the second argument. SOURCE /src/lib9/nan.c