clog(3M)

DESCRIPTION

These functions are available only for IA-64.

clog() returns the complex natural logarithm of z in the range of a strip mathematically unbounded along the real axis and in the interval [-iPi,+iPi] along the imaginary axis. There is a branch cut along the negative real axis.

clogf() is a float complex version of clog(); it takes a float complex argument and returns a float complex result.

USAGE

To use these functions, compile with the default -Ae option. Make sure your program includes <complex.h>. Link in the math library by specifying -lm on the compiler or linker command line.

RETURN VALUES

clog(conj(z)) = conj(clog(z)).

clog(-0+i0) returns -Inf+iPi and raises the divide- by-zero floating-point exception.

clog(+0+i0) returns -Inf+i0 and raises the divide-by- zero floating-point exception.

clog(x+iInf) returns +Inf+iPi/2, for finite x.

clog(x+iNaN) returns NaN+iNaN and optionally raises the invalid floating-point exception, for finite x.

clog(-Inf+iy) returns +Inf+iPi, for finite positive-signed y.

clog(+Inf+iy) returns +Inf+i0, for finite positive-signed y.

clog(-Inf+iInf) returns +Inf+i3Pi/4.

clog(+Inf+iInf) returns +Inf+ipi/4.

clog(±Inf+iNaN) returns +Inf+iNaN.

clog(NaN+iy) returns NaN+iNaN and optionally raises the invalid floating-point exception, for finite y.

clog(NaN+iInf) returns +Inf+iNaN.

clog(NaN+iNaN) returns NaN+iNaN.

ERRORS

No errors are defined.

SEE ALSO

log(3M), cexp(3M), complex(5).

STANDARDS CONFORMANCE

clog(), clogf(): ISO/IEC C99 (including Annex G, IEC 60559-compatible complex arithmetic)