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CLOG(3)                  BSD Library Functions Manual                  CLOG(3)

NAME
     clog -- complex logarithm function

SYNOPSIS
     #include <complex.h>

     double complex
     clog(double complex z);

     long double complex
     clogl(long double complex z);

     float complex
     clogf(float complex z);

DESCRIPTION
     clog(z) returns the complex logarithm of z.

     clog(conj(z)) = conj(clog(z)), for all complex floating-point numbers z.

SPECIAL VALUES
     The conjugate symmetry of clog() is used to abbreviate the specification of special values.

     clog(-0 + 0i) returns -inf + Pi i and raises the divide-by-zero flag.

     clog(0 + 0i) returns -inf + 0i and raises the divide-by-zero flag.

     clog(x + inf i) returns inf + Pi/2 i, for finite x.

     clog(x + NaN i) returns NaN + NaN i.

     clog(-inf + yi) returns inf + Pi i, for finite positive y.

     clog(inf + yi) returns inf + 0i, for finite positive y.

     clog(-inf + inf i) returns inf + 3Pi/4 i.

     clog(inf + inf i) returns inf + Pi/4 i.

     clog(+-inf + NaN i) returns inf + NaN i.

     clog(NaN + yi) returns NaN + NaN i, for finite y.

     clog(NaN + inf i) returns inf + NaN i.

     clog(NaN + NaN i) returns NaN + NaN i.

NOTES
SEE ALSO
     cexp(3) log(3) complex(3)

STANDARDS
     The clog() function conforms to ISO/IEC 9899:1999(E).

4th Berkeley Distribution      November 9, 2006      4th Berkeley Distribution