man3/clog.3

   1 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
   2 .\" Distributed under GPL
   3 .\"
   4 .TH CLOG 3 2002-07-28 "" "complex math routines"
   5 .SH NAME
   6 clog, clogf, clogl \- natural logarithm of a complex number
   7 .SH SYNOPSIS
   8 .B #include <complex.h>
   9 .sp
  10 .BI "double complex clog(double complex " z );
  11 .br
  12 .BI "float complex clogf(float complex " z );
  13 .br
  14 .BI "long double complex clogl(long double complex " z );
  15 .sp
  16 Link with \-lm.
  17 .SH DESCRIPTION
  18 The logarithm clog() is the inverse function of the exponential cexp().
  19 Thus, if y = clog(z), then z = cexp(y).
  20 The imaginary part of
  21 .I y
  22 is chosen in the interval [\-pi,pi].
  23 .LP
  24 One has clog(z) = log(cabs(z))+I*carg(z).
  25 .LP
  26 Note that
  27 .I z
  28 close to zero will cause an overflow.
  29 .SH "CONFORMING TO"
  30 C99
  31 .SH "SEE ALSO"
  32 .BR cabs (3),
  33 .BR cexp (3),
  34 .BR clog10 (3),
  35 .BR complex (7)