man3/catan.3

   1 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
   2 .\" Distributed under GPL
   3 .\"
   4 .TH CATAN 3 2002-07-28 "" "complex math routines"
   5 .SH NAME
   6 catan, catanf, catanl \- complex arc tangents
   7 .SH SYNOPSIS
   8 .B #include <complex.h>
   9 .sp
  10 .BI "double complex catan(double complex " z );
  11 .sp
  12 .BI "float complex catanf(float complex " z );
  13 .sp
  14 .BI "long double complex catanl(long double complex " z );
  15 .sp
  16 Link with \-lm.
  17 .SH DESCRIPTION
  18 The catan() function calculates the complex atan().
  19 If y = catan(z), then z = ctan(y).
  20 The real part of y is chosen in the interval [-pi/2,pi/2].
  21 .LP
  22 One has
  23 catan(z) = 1/2i clog((1+iz)/(1-iz)).
  24 .SH "CONFORMING TO"
  25 C99
  26 .SH "SEE ALSO"
  27 .BR ccos (3),
  28 .BR clog (3),
  29 .BR complex (5)