Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

ilogbl(3m) [opensolaris man page]

ilogb(3M)						  Mathematical Library Functions						 ilogb(3M)

NAME
ilogb, ilogbf, ilogbl - return an unbiased exponent SYNOPSIS
c99 [ flag... ] file... -lm [ library... ] #include <math.h> int ilogb(double x); int ilogbf(float x); int ilogbl(long double x); cc [ flag... ] file... -lm [ library... ] #include <math.h> int ilogb(double x); int ilogbf(float x); int ilogbl(long double x); DESCRIPTION
These functions return the exponent part of their argument x. Formally, the return value is the integral part of log(r)| x | as a signed integral value, for non-zero x, where r is the radix of the machine's floating point arithmetic, which is the value of FLT_RADIX defined in <float.h>. RETURN VALUES
Upon successful completion, these functions return the exponent part of x as a signed integer value. They are equivalent to calling the corresponding logb(3M) function and casting the returned value to type int. If x is 0, the value FP_ILOGB0 is returned. For SUSv3-conforming applications compiled with the c99 compiler driver (see standards(5)), a domain error occurs. If x is +-Inf, the value INT_MAX is returned. For SUSv3-conforming applications compiled with the c99 compiler driver, a domain error occurs. If x is NaN, the value FP_ILOGBNAN is returned. For SUSv3-conforming applications compiled with the c99 compiler driver, a domain error occurs. ERRORS
These functions will fail if: Domain Error The x argument is zero, NaN, or +-Inf. If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, then the invalid floating-point exception is raised. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ SEE ALSO
feclearexcept(3M), fetestexcept(3M), limits.h(3HEAD), logb(3M), math.h(3HEAD), scalb(3M), attributes(5), standards(5) SunOS 5.11 12 Jul 2006 ilogb(3M)

Check Out this Related Man Page

logb(3M)						  Mathematical Library Functions						  logb(3M)

NAME
logb, logbf, logbl - radix-independent exponent SYNOPSIS
c99 [ flag... ] file... -lm [ library... ] #include <math.h> double logb(double x); float logbf(float x); long double logbl(long double x); cc [ flag... ] file... -lm [ library... ] #include <math.h> double logb(double x); float logbf(float x); long double logbl(long double x); DESCRIPTION
These functions compute the exponent of x, which is the integral part of log(r) |x|, as a signed floating point value, for non-zero x, where r is the radix of the machine's floating-point arithmetic, which is the value of FLT_RADIX defined in the <float.h> header. RETURN VALUES
Upon successful completion, these functions return the exponent of x. If x is subnormal: o For SUSv3-conforming applications compiled with the c99 compiler driver (see standards(5)), the exponent of x as if x were nor- malized is returned. o Otherwise, if compiled with the cc compiler driver, -1022, -126, and -16382 are returned for logb(), logbf(), and logbl(), respectively. If x is +-0, a pole error occurs and logb(), logbf(), and logbl() return -HUGE_VAL, -HUGE_VALF, and -HUGE_VALL, respectively. If x is NaN, a NaN is returned. If x is +-Inf, +Inf is returned. ERRORS
These functions will fail if: Pole Error The value of x is +-0. If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, the divide-by-zero floating-point exception is raised. The logb() function sets errno to EDOM if the value of x is 0. USAGE
An application wanting to check for exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception has been raised. An application should either examine the return value or check the floating point exception flags to detect exceptions. An application can also set errno to 0 before calling logb(). On return, if errno is non-zero, an error has occurred. The logbf() and logbl() functions do not set errno. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ SEE ALSO
feclearexcept(3M), fetestexcept(3M), ilogb(3M), math.h(3HEAD), matherr(3M), scalb(3M), attributes(5), standards(5) SunOS 5.11 12 Jul 2006 logb(3M)
Man Page

Featured Tech Videos