fanotify_init.2, fanotify.7: Document FAN_REPORT_TID

[thirdparty/man-pages.git] / man3 / catan.3

diff --git a/man3/catan.3 b/man3/catan.3
index 2d22a4e452ef06cd5eb1b78d23524894d5e3393a..868ba96ddc8d4bc81cd7ae769f42f14eb89f0f8a 100644 (file)
--- a/man3/catan.3
+++ b/man3/catan.3
@@ -1,31 +1,85 @@
 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
+.\" and Copyright (C) 2011 Michael Kerrisk <mtk.manpages@gmail.com>
+.\"
+.\" %%%LICENSE_START(GPL_NOVERSION_ONELINE)
 .\" Distributed under GPL
+.\" %%%LICENSE_END
 .\"
-.TH CATAN 3 2002-07-28 "" "Linux Programmer's Manual"
+.TH CATAN 3 2015-04-19 "" "Linux Programmer's Manual"
 .SH NAME
 catan, catanf, catanl \- complex arc tangents
 .SH SYNOPSIS
 .B #include <complex.h>
-.sp
+.PP
 .BI "double complex catan(double complex " z );
 .br
 .BI "float complex catanf(float complex " z );
 .br
 .BI "long double complex catanl(long double complex " z );
-.sp
-Link with \-lm.
+.PP
+Link with \fI\-lm\fP.
 .SH DESCRIPTION
-The
-.BR catan ()
-function calculates the complex atan().
-If y = catan(z), then z = ctan(y).
+These functions calculate the complex arc tangent of
+.IR z .
+If \fIy\ =\ catan(z)\fP, then \fIz\ =\ ctan(y)\fP.
 The real part of y is chosen in the interval [\-pi/2,pi/2].
-.LP
-One has
-catan(z) = 1 / 2i clog((1 + iz) / (1 \- iz)).
-.SH "CONFORMING TO"
-C99
-.SH "SEE ALSO"
+.PP
+One has:
+.PP
+.nf
+    catan(z) = (clog(1 + i * z) \- clog(1 \- i * z)) / (2 * i)
+.fi
+.SH VERSIONS
+These functions first appeared in glibc in version 2.1.
+.SH ATTRIBUTES
+For an explanation of the terms used in this section, see
+.BR attributes (7).
+.TS
+allbox;
+lbw27 lb lb
+l l l.
+Interface      Attribute       Value
+T{
+.BR catan (),
+.BR catanf (),
+.BR catanl ()
+T}     Thread safety   MT-Safe
+.TE
+.SH CONFORMING TO
+C99, POSIX.1-2001, POSIX.1-2008.
+.SH EXAMPLE
+.EX
+/* Link with "\-lm" */
+
+#include <complex.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+
+int
+main(int argc, char *argv[])
+{
+    double complex z, c, f;
+    double complex i = I;
+
+    if (argc != 3) {
+        fprintf(stderr, "Usage: %s <real> <imag>\\n", argv[0]);
+        exit(EXIT_FAILURE);
+    }
+
+    z = atof(argv[1]) + atof(argv[2]) * I;
+
+    c = catan(z);
+    printf("catan() = %6.3f %6.3f*i\\n", creal(c), cimag(c));
+
+    f = (clog(1 + i * z) \- clog(1 \- i * z)) / (2 * i);
+    printf("formula = %6.3f %6.3f*i\\n", creal(f2), cimag(f2));
+
+    exit(EXIT_SUCCESS);
+}
+.EE
+.SH SEE ALSO
 .BR ccos (3),
 .BR clog (3),
+.BR ctan (3),
 .BR complex (7)